WorldWideScience

Sample records for apoptosis bcl-2 proteins

  1. The Expression of Apoptosis-Related Genes Bcl-2 and Bax Protein and Apoptosis Positivity in Cervical Carcinoma during Irradiation

    Institute of Scientific and Technical Information of China (English)

    ZHAODongli; SHIJingsen; LIMingzhong; SONGLiping; WANGShuwen

    2005-01-01

    Objective: To evaluate the apoptosis positivity, the expression of Bcl-2. bax proteins in 30 patients with squamous cell cervix carcinoma before and after radiotherapy. Methods: By using immunohistochemical and TDT-dUTP nick end labelling techniques. 30 cases of squamous cell cervical carcinoma were analyzed. Results: The apoptosis positivity before and after irradiation was 76.7%, and 100% respectively, with the difference being significant (P<0.05); The positive rates of Bcl-2 protein before and after irradiation were 73.3% and 46.7% respectively, with the difference being significant (P<0.05): The positive rates of bax protein before and after irradiation were 86% and 100 respectively, with the difference being significant (P<0.05). Conclusion: bax and Bcl-2 protein play an important role in apoptosis induced by fractionated radiation therapy. Apoptosis induced by irradiation is contributed to upregulation of bax protein or downregulation of Bcl-2 protein.

  2. Effects of apoptosis-related proteins caspase-3, Bax and Bcl-2 on cerebral ischemia rats

    OpenAIRE

    Liu, Guangyi; Tao WANG; WANG, TINGING; Song, Jinming; Zhou, Zhen

    2013-01-01

    Neuron apoptosis is known to mediate a change of ethology following cerebral ischemia-reperfusion injury in rats. Additionally, Bcl-2, Bax and caspase-3 proteins may exert a significant effect on neuron injury. The aim of this study was to investigate the role, mechanism of action and clinical significance of these proteins in neuron apoptosis and functional impairment following cerebral ischemia-reperfusion injury in rats. Sixty male healthy adult Wistar rats were randomly assigned into cont...

  3. Extracellular Administration of BCL2 Protein Reduces Apoptosis and Improves Survival in a Murine Model of Sepsis

    Science.gov (United States)

    Iwata, Akiko; de Claro, R. Angelo; Morgan-Stevenson, Vicki L.; Tupper, Joan C.; Schwartz, Barbara R.; Liu, Li; Zhu, Xiaodong; Jordan, Katherine C.; Winn, Robert K.; Harlan, John M.

    2011-01-01

    Background Severe sepsis and septic shock are major causes of morbidity and mortality worldwide. In experimental sepsis there is prominent apoptosis of various cell types, and genetic manipulation of death and survival pathways has been shown to modulate organ injury and survival. Methodology/Principal Findings We investigated the effect of extracellular administration of two anti-apoptotic members of the BCL2 (B-cell lymphoma 2) family of intracellular regulators of cell death in a murine model of sepsis induced by cecal ligation and puncture (CLP). We show that intraperitoneal injection of picomole range doses of recombinant human (rh) BCL2 or rhBCL2A1 protein markedly improved survival as assessed by surrogate markers of death. Treatment with rhBCL2 or rhBCL2A1 protein significantly reduced the number of apoptotic cells in the intestine and heart following CLP, and this was accompanied by increased expression of endogenous mouse BCL2 protein. Further, mice treated with rhBCL2A1 protein showed an increase in the total number of neutrophils in the peritoneum following CLP with reduced neutrophil apoptosis. Finally, although neither BCL2 nor BCL2A1 are a direct TLR2 ligand, TLR2-null mice were not protected by rhBCL2A1 protein, indicating that TLR2 signaling was required for the protective activity of extracellularly adminsitered BCL2A1 protein in vivo. Conclusions/Significance Treatment with rhBCL2A1 or rhBCL2 protein protects mice from sepsis by reducing apoptosis in multiple target tissues, demonstrating an unexpected, potent activity of extracellularly administered BCL2 BH4-domain proteins. PMID:21390214

  4. Effects of genistein on neuronal apoptosis, and expression of Bcl-2 and Bax proteins in the hippocampus of ovariectomized rats

    Institute of Scientific and Technical Information of China (English)

    Yun Peng; Bo Jiang; Huiling Wu; Ruchun Dai; Liming Tan

    2012-01-01

    Genistein is one of several isoflavones that has a structure similar to 17β-estradiol, has a strong antioxidant effect, and a high affinity to estrogen receptors. At 15 weeks after ovariectomy, the expression of Bcl-2 in the hippocampus of rats decreased and Bax expression increased, with an obvious upregulation of apoptosis. However, intraperitoneal injection of genistein or 17β-estradiol for 15 consecutive weeks from the second day after operation upregulated Bcl-2 protein expression, downregulated Bax protein expression, and attenuated hippocampal neuron apoptosis. Our experimental findings indicate that long-term intervention with genistein can lead to a decrease in apoptosis in hippocampal neurons following ovariectomy, upregulate the expression of Bcl-2, and downregulate the expression of Bax. In addition, genistein and 17β-estradiol play equal anti-apoptotic and neuroprotective roles.

  5. Apoptosis and proliferative activity of non-Hodgkin's lymphoma: correlation with Bcl-2 and P53 protein expression

    International Nuclear Information System (INIS)

    Tumor growth in a given neoplasm is the net result of cell proliferation and cell loss, and apoptosis is the most significant component of continuous cell loss in most tumors. In this study, we examined non-Hodgkin's lymphoma (NHL, n = 67) immunohistochemically for the presence of Bcl-2 oncoprotein and P53 protein and compared apoptotic indices (Als) and Ki-67 proliferative indices (percentages of Ki-67 positive cells). 67 patients with NHL were evaluated: 3 low-grade and 64 intermediate-grade. The phenotype was determined in 65 cases: 47 (70%) were B cell type and 18 (27%) were T cell type. Als and Ki-67 proliferative indices were determined immunohistochemically and the overexpression of P53 and Bcl-2 protein were also evaluated. The overexpressions of Bcl-2 protein and P53 protein were found in 40% (26/65) and 31% (20/65). The Al ranged from 0% to 15% (mean 2.61, median 1.2). Cellular Bcl-2, which counteracts apoptosis, was significantly (ρ = 0.005) associated with Als. Ki-67 proliferative indices ranged from 1% to 91% (mean 55.4), and P53 was significantly (ρ 0.000) associated with Ki-67 proliferative indices. A positive correlation between Als and Ki-67 proliferative indices was revealed (ρ = 0.012) in Bcl-2 positive patients. In NHL, we observed a correlation between Als and Bcl-2 expression, between Ki-67 proliferative indices and P53 expression, and between Als and Ki-67 proliferative indices in Bcl-2 positive patients. Our results suggest that cell apoptosis may be inseparable from cell proliferation during tumor growth

  6. Effects of low dose radiation on tumor apoptosis, cell cycle progression and changes of apoptosis-related protein bcl-2 in tumor-bearing mice

    International Nuclear Information System (INIS)

    Objective: To study the effect of low dose radiation (LDR) on tumor apoptosis, cell cycle progression and changes of apoptosis-related protein bcl-2 in tumor-bearing mice. Methods: Kunming stain male mice were implanted with S180 sarcoma cells in the left inguen subcutaneously as an in situ experimental animal model. Seven days after implantation, the mice were given 75 mGy whole-body γ-irradiation. At 24 and 48 h after irradiation, all mice were sacrificed to measure the tumor volume, and tumor cell apoptosis, cell cycle progression were analyzed by flow cytometry. The expression of apoptosis-related protein bcl-2 and the apoptotic rate of tumor cells were observed by immunohistochemistry and electron microscopy. Results: Tumor growth was significantly slowed down after LDR (P1 phase and the expression of bcl-2 protein decreased at 24 h. Apoptotic rate of tumor cells increased significantly at 48 h after LDR. Conclusion: LDR could cause a G1-phase arrest and increase the apoptosis of tumor cells through the low level of apoptosis-related protein bcl-2 in the tumor-bearing mice. The organized immune function and anti-tumor ability are markedly increased after LDR. The study provides practical evidence of clinical application to cancer treatment

  7. Effects of Low Dose Radiation on Tumor Apoptosis, Cell Cycle and Apoptosis-Related Protein Bcl-2 in Tumor-Bearing Mice

    Institute of Scientific and Technical Information of China (English)

    YUHongsheng; SONGAiqin; FEIConghe; WANGZhuomin; QIUWensheng

    2005-01-01

    Objective: To study the effects of low dose radiation (LDR) on tumor apoptosis, cell cycle progression and changes of apoptosis-related protein Bcl-2 in tumor-bearing mice. Methods: Male mice of Kunming strain were implanted subcutaneously with S180 sarcoma cells in the left inguen as an in situ experimental animal model. Seven days later, the mice were subjected to 75 mGy whole-body γ-irradiation.At 24 and 48 h after the irradiation, all mice were sacrificed. The tumor sizes were measured, and tumor cell apoptosis and cell cycle progression were analyzed by flow cytometry. The expression of apoptosisrelated protein Bcl-2 and the apoptotic rate of tumor cells were observed by immunohistochemistry and electron microscopy. Results: Tumors grew significantly slower after LDR (P<0.05). The tumor cells were arrested in G1 phrase and the expression of Bcl-2 protein decreased at 24 h. Apoptotic rate of tumor cells was increased significantly at 48 h after LDR (P<0.01). Conclusion: LDR could cause a Gl-phase arrest and increase the apoptosis of tumor cells through the low level of apoptosis-related protein bcl-2 in the tumor-bearing mice. The organized immune function and anti-tumor ability are markedly increased after LDR. Our study provides practical evidence of clinical application to cancer treatment.

  8. Signal transduction mediated by Bid, a pro-death Bcl-2 family proteins, connects the death receptor and mitochondria apoptosis pathways

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Two major apoptosis pathways have been defined in mammalian cells, the Fas/TNF-R1 death receptor pathway and the mitochondria pathway. The Bcl-2 family proteins consist of both anti-apoptosis and pro- apoptosis members that regulate apoptosis, mainly by controlling the release of cytochrome c and other mitochondrial apoptotic events. However, death signals mediated by Fas/TNF-R1 receptors can usually activate caspases directly, bypassing the need for mitochondria and escaping the regulation by Bcl-2 family proteins. Bid is a novel pro-apoptosis Bcl-2 family protein that is activated by caspase 8 in response to Fas/TNF-R1 death receptor signals. Activated Bid is translocated to mitochondria and induces cytochrome c release, which in turn activates downstream caspases. Such a connection between the two apoptosis pathways could be important for induction of apoptosis in certain types of cells and responsible for the pathogenesis of a number of human diseases.

  9. Bcl-2 gene therapy for apoptosis following traumatic brain injury

    Institute of Scientific and Technical Information of China (English)

    YANG Xiao-feng; ZHENG Xue-sheng; LIU Wei-guo; FENG Jun-feng

    2006-01-01

    Objective: To investigate the therapeutic effect of Bcl- 2 fusion protein on apoptosis in brain following traumatic brain injury.Methods: Bcl-2 gene was cloned by RT-PCR. Bcl-2 and EGFP genes were linked together and inserted into pAdeno-X vector. This recombinant vector was packaged into infectious adenovirus in HEK293 cells. Ninety Wistar rats were assigned randomly into experimental group(n=45) and control group (n=45). All rats were subjected to traumatic brain injury. Then recombinant adenovirus (for experimental group) or saline (for control group) was injected into the traumatic brain. The expression of Bcl-2 fusion protein was investigated by Western blotting, immunohistochemistry and fluorescence microscopy. Apoptosis in the injured brain was studied by TUNEL. Animals' behavior capacity was evaluated by tiltboard test.Results: In the experimental group, many fluorescent cells were found around the traumatic locus,which were also proven to be Bcl-2-positive by immunohistochemistry. On the contrary, few Bcl-2-positive cells and no fluorescent cell were detected in the control group. Bcl-2 expression of experimental group was much higher than that of control group, which was illustrated by Western blotting. The apoptosis index of experimental group was 0.027 ± 0.005, and that of control group was 0.141±0.025 (P<0.01). Two weeks after injury, animals of the experimental group behaved better than those of the control group.Conclusions: A recombinant adenovirus vector expressing Bcl-2 fusion protein has been constructed. Bcl-2 fusion protein can suppress apoptosis and promote cell survival. Moreover, the behavior recovery of the injured animal is promoted. Bcl-2 fusion protein provides a way to track the target cells in vivo.

  10. Arsenite induces apoptosis in human mesenchymal stem cells by altering Bcl-2 family proteins and by activating intrinsic pathway

    International Nuclear Information System (INIS)

    Purpose: Environmental exposure to arsenic is an important public health issue. The effects of arsenic on different tissues and organs have been intensively studied. However, the effects of arsenic on bone marrow mesenchymal stem cells (MSCs) have not been reported. This study is designed to investigate the cell death process caused by arsenite and its related underlying mechanisms on MSCs. The rationale is that absorbed arsenic in the blood circulation can reach to the bone marrow and may affect the cell survival of MSCs. Methods: MSCs of passage 1 were purchased from Tulane University, grown till 70% confluency level and plated according to the experimental requirements followed by treatment with arsenite at various concentrations and time points. Arsenite (iAsIII) induced cytotoxic effects were confirmed by cell viability and cell cycle analysis. For the presence of canonic apoptosis markers; DNA damage, exposure of intramembrane phosphotidylserine, protein and m-RNA expression levels were analyzed. Results: iAsIII induced growth inhibition, G2-M arrest and apoptotic cell death in MSCs, the apoptosis induced by iAsIII in the cultured MSCs was, via altering Bcl-2 family proteins and by involving intrinsic pathway. Conclusion: iAsIII can induce apoptosis in bone marrow-derived MSCs via Bcl-2 family proteins, regulating intrinsic apoptotic pathway. Due to the multipotency of MSC, acting as progenitor cells for a variety of connective tissues including bone, adipose, cartilage and muscle, these effects of arsenic may be important in assessing the health risk of the arsenic compounds and understanding the mechanisms of arsenic-induced harmful effects.

  11. Acidosis promotes Bcl-2 family-mediated evasion of apoptosis: involvement of acid-sensing G protein-coupled receptor Gpr65 signaling to Mek/Erk.

    Science.gov (United States)

    Ryder, Christopher; McColl, Karen; Zhong, Fei; Distelhorst, Clark W

    2012-08-10

    Acidosis arises in solid and lymphoid malignancies secondary to altered nutrient supply and utilization. Tumor acidosis correlates with therapeutic resistance, although the mechanism behind this effect is not fully understood. Here we show that incubation of lymphoma cell lines in acidic conditions (pH 6.5) blocks apoptosis induced by multiple cytotoxic metabolic stresses, including deprivation of glucose or glutamine and treatment with dexamethasone. We sought to examine the role of the Bcl-2 family of apoptosis regulators in this process. Interestingly, we found that acidic culture causes elevation of both Bcl-2 and Bcl-xL, while also attenuating glutamine starvation-induced elevation of p53-up-regulated modulator of apoptosis (PUMA) and Bim. We confirmed with knockdown studies that these shifts direct survival decisions during starvation and acidosis. Importantly, the promotion of a high anti- to pro-apoptotic Bcl-2 family member ratio by acidosis renders cells exquisitely sensitive to the Bcl-2/Bcl-xL antagonist ABT-737, suggesting that acidosis causes Bcl-2 family dependence. This dependence appears to be mediated, in part, by the acid-sensing G protein-coupled receptor, GPR65, via a MEK/ERK pathway. PMID:22685289

  12. AMP-activated protein kinase mediates apoptosis in response to bioenergetic stress through activation of the pro-apoptotic Bcl-2 homology domain-3-only protein BMF.

    Science.gov (United States)

    Kilbride, Seán M; Farrelly, Angela M; Bonner, Caroline; Ward, Manus W; Nyhan, Kristine C; Concannon, Caoimhín G; Wollheim, Claes B; Byrne, Maria M; Prehn, Jochen H M

    2010-11-12

    Heterozygous loss-of-function mutations in the hepatocyte nuclear factor 1A (HNF1A) gene result in the pathogenesis of maturity-onset diabetes-of-the-young type 3, (HNF1A-MODY). This disorder is characterized by a primary defect in metabolism-secretion coupling and decreased beta cell mass, attributed to excessive beta cell apoptosis. Here, we investigated the link between energy stress and apoptosis activation following HNF1A inactivation. This study employed single cell fluorescent microscopy, flow cytometry, gene expression analysis, and gene silencing to study the effects of overexpression of dominant-negative (DN)-HNF1A expression on cellular bioenergetics and apoptosis in INS-1 cells. Induction of DN-HNF1A expression led to reduced ATP levels and diminished the bioenergetic response to glucose. This was coupled with activation of the bioenergetic stress sensor AMP-activated protein kinase (AMPK), which preceded the onset of apoptosis. Pharmacological activation of AMPK using aminoimidazole carboxamide ribonucleotide (AICAR) was sufficient to induce apoptosis in naive cells. Conversely, inhibition of AMPK with compound C or AMPKα gene silencing protected against DN-HNF1A-induced apoptosis. Interestingly, AMPK mediated the induction of the pro-apoptotic Bcl-2 homology domain-3-only protein Bmf (Bcl-2-modifying factor). Bmf expression was also elevated in islets of DN-HNF1A transgenic mice. Furthermore, knockdown of Bmf expression in INS-1 cells using siRNA was sufficient to protect against DN-HNF1A-induced apoptosis. Our study suggests that overexpression of DN-HNF1A induces bioenergetic stress and activation of AMPK. This in turn mediates the transcriptional activation of the pro-apoptotic Bcl-2-homology protein BMF, coupling prolonged energy stress to apoptosis activation. PMID:20841353

  13. MPT64 Protein from Mycobacterium tuberculosis Inhibits Apoptosis of Macrophages through NF-kB-miRNA21-Bcl-2 Pathway

    Science.gov (United States)

    Wang, Qingmin; Liu, Shupeng; Tang, Ying; Liu, Qiuhong; Yao, Yongjie

    2014-01-01

    MPT64 is one of the secreted proteins from Mycobacterium tuberculosis. Little is known about its role in infection by Mycobacterium tuberculosis. In this study, we demonstrated that MPT64 could dose-dependently inhibit the apoptosis of RAW264.7 macrophages induced by PPD-BCG. Quantitative real-time PCR results showed that the expression of bcl-2 increased in macrophages treated with MPT64 compared with PPD-treated cells. Furthermore, the results provided strong evidence that bcl-2 up-regulation was positively controlled by miRNA-21. Finally, NF-κB was identified as the transcription factor for miRNA-21 using a ChIP assay. It can be concluded from our study that MPT64 could inhibit the apoptosis of RAW264.7 macrophages through the NF-κB-miRNA21-Bcl-2 pathway. PMID:25000291

  14. Effects of Bisphenol A on apoptosis of spermatogenic cells and expression of Bax and Bcl-2 proteins in the Siberian frog Rana chensinensis

    OpenAIRE

    LIN Sheng-Nan; Zhang, Yu-hui

    2008-01-01

    In order to investigate the effects of bisphenol A (BPA) on apoptosis and the expression levels of Bax and Bcl-2 protein in amphibian spermatogenic cells, we treated Rana chensinensis with concentrations of 10-7, 10-6, 10-5mol/L BPA respectively. Testes were removed after R.chensinensis had been treated for 3 , 5 or 7 days. Apoptotic cells were examined by TUNEL and Methyl Green-Pyronine. The expression levels of Bax and Bcl-2 protein in spermatogenic cells were detected by immunohistochemic...

  15. Acidosis Promotes Bcl-2 Family-mediated Evasion of Apoptosis

    Science.gov (United States)

    Ryder, Christopher; McColl, Karen; Zhong, Fei; Distelhorst, Clark W.

    2012-01-01

    Acidosis arises in solid and lymphoid malignancies secondary to altered nutrient supply and utilization. Tumor acidosis correlates with therapeutic resistance, although the mechanism behind this effect is not fully understood. Here we show that incubation of lymphoma cell lines in acidic conditions (pH 6.5) blocks apoptosis induced by multiple cytotoxic metabolic stresses, including deprivation of glucose or glutamine and treatment with dexamethasone. We sought to examine the role of the Bcl-2 family of apoptosis regulators in this process. Interestingly, we found that acidic culture causes elevation of both Bcl-2 and Bcl-xL, while also attenuating glutamine starvation-induced elevation of p53-up-regulated modulator of apoptosis (PUMA) and Bim. We confirmed with knockdown studies that these shifts direct survival decisions during starvation and acidosis. Importantly, the promotion of a high anti- to pro-apoptotic Bcl-2 family member ratio by acidosis renders cells exquisitely sensitive to the Bcl-2/Bcl-xL antagonist ABT-737, suggesting that acidosis causes Bcl-2 family dependence. This dependence appears to be mediated, in part, by the acid-sensing G protein-coupled receptor, GPR65, via a MEK/ERK pathway. PMID:22685289

  16. The function of apoptosis and protein expression of bcl-2, p53 and C-myc inthe development of gastric cancer

    Institute of Scientific and Technical Information of China (English)

    An Gao Xu; Shao Guang Li; Ji Hong Liu; Ai Hua Gan

    2000-01-01

    AIM To understand the rule and possible function of apoptosis and protein expression of bcl-2, p53 and C-myc in chronic gastritis, gastric ulcer, non-classic proliferation of gastric mucosa and gastric cancer.METHODS Apoptosis was detected by using in situ terminal labelling (TUNEL). The protein expression ofbcl-2, p53 and C-myc was detected by immunohistochemical method.RESULTS The indexes of apoptosis in chronic active gastritis, gastric ulcer, mild and severe non-classicproliferation of gastric mucosa, early and progressive gastric cancer were 16.8%±12.3%, 24.1%±20.0%,19.3%±16.4%, 15.7%±15.2%, 10.1%±9.1% and 6.3%±6.0%, respectively. The index of progressivegastric cancer was lower than that of early gastric cancer and non-classic proliferation of gastric mucosa(P<0.05). The positive rate of bcl-2 protein was 9.4%, 27.6%, 52.9%, 75.0%, 83.3% and 46.7%,respectively. The positive rate of bcl-2 of early gastric cancer was higher than that of progressive gastriccancer. The positive rates of p53 protein of severe non-classic proliferation, early and progressive gastriccancer were 25.0%, 33.3% and 63.3%, respectively. The positive rate of p53 of progressive gastric cancerwas higher than that of early gastric cancer and non-classic proliferation (P<0.05). In Lauren types, theindex of apoptosis, protein expression rates of bcl-2, p53 and C-myc of intestinal type were 8.3%±7.2%,38.9%, 77.7% and 56.6%, while that of diffuse type were 5.1%±4.9%, 58.3%, 50.0% and 8.3%,respectively. All markers had statistical difference between two types (P<0.05).CONCLUSION Apoptosis was inhibited stepwise in the development of non-classic proliferation of gastricmucosa to early gastric cancer and then to progressive gastric cancer. The high expression of bcl-2, p53 andC-myc was related to the development of gastric cancer, bcl-2 might play an important role in early gastriccancer while p53 and C-myc act mostly in middle and late stage gastric cancer. The Lauren typing of

  17. Dioscin-induced apoptosis of human LNCaP prostate carcinoma cells through activation of caspase-3 and modulation of Bcl-2 protein family.

    Science.gov (United States)

    Chen, Jing; Li, Hui-min; Zhang, Xue-nong; Xiong, Chao-mei; Ruan, Jin-lan

    2014-02-01

    Dioscin is a natural steroid saponin derived from several plants, showing potent anti-cancer effect against a variety of tumor cell lines. In the present study, we investigated the anti-cancer activity of dioscin against human LNCaP cells, and evaluated the possible mechanism involved in its antineoplastic action. It was found that dioscin (1, 2 and 4 μmol/L) could significantly inhibit the viability of LNCaP cells in a time- and concentration-dependent manner. Flow cytometry revealed that the apoptosis rate was increased after treatment of LNCaP cells with dioscin for 24 h, indicating that apoptosis was an important mechanism by which dioscin inhibited cancer. Western blotting was employed to detect the expression of caspase-3, Bcl-2 and Bax in LNCaP cells. The expression of cleaved caspase-3 was significantly increased, and meanwhile procaspase-3 was markedly decreased. The expression of anti-apoptotic protein Bcl-2 was down-regulated, whereas the pro-apoptotic protein Bax was up-regulated. Moreover, the Bcl-2/Bax ratio was drastically decreased. These results suggested that dioscin possessed potential anti-tumor activity in human LNCaP cells through the apoptosis pathway, which might be associated with caspase-3 and Bcl-2 protein family. PMID:24496691

  18. Effect of compound preparation Tongqiao Jiannao capsules on neural cell apoptosis and Bcl-2 and Bax protein levels in a rat model of brain ischemia/reperfusion injury

    Institute of Scientific and Technical Information of China (English)

    Rui Wang; Guanglai Li; Wei Wang; Huanying Li

    2008-01-01

    BACKGROUND: Pharmacological studies have demonstrated that compound preparation Tongqiao Jiannao capsules composed of Zexie, Baizhu, Honghua, Danshen, and Shexiang can supplement qi,activate blood circulation, relieve blood stasis, induce resuscitation for alleviating pain, relieve pain, anddilate blood vessels.OBJECTIVE: To observe the effects of Tongqiao Jiannao capsules on the levels of the anti-apoptotic protein Bcl-2 and the pro-apoptotic protein Bax, and verify the mechanism of action.DESIGN, TIME AND SETTING: Randomized, controlled animal experiment, performed in the Laboratory of Biochemistry and Molecular Biology, Shanxi Medical University between June 2001 and December 2002.MATERIALS: The right middle cerebral arteries of 24 healthy adult Sprague Dawley rats were occluded by the suture method. The primary Chinese herbal medicinal ingredients of Tongqiao Jiannao capsules are Zexie. Baizhu, Honghua, Danshen, and Shexiang, which were purchased from Shanxi Provincial Medicinal Material Company, China, and prepared into condensed granules in the Room for Chinese Herbal Medicine Preparation, Second Hospital, Shanxi Medical University. Bcl-2 and Bax immunohistochemical staining kits, a 3,3-diaminobenzidine(DAB) kit, and an in situ apoptosis detection kit were purchased from Wuhan Boster Bioengineering Co., Ltd., China.METHODS: Twenty-four rats were randomly and evenly divided into three groups: (1) sham-operated rats in which sutures were inserted and immediately pulled out; (2) Tongqiao Jiannao capsule-treated rats that were intragastrically administered 6.5 g/kg/d Tongqiao Jiannao capsule preparation for seven successive days prior to middle cerebral artery occlusion (MCAO); and (3) MCAO rats without any other treatments.MAIN OUTCOME MEASURES: The levels of neural cell apoptosis and Bcl-2 and Bax proteins at 24 hours post-surgery.RESULTS: In the MCAO group, the numbers of apoptotic cells and Bax-positive cells were significantly increased, while the numbers of

  19. Histone demethylase Jmjd3 regulates osteoblast apoptosis through targeting anti-apoptotic protein Bcl-2 and pro-apoptotic protein Bim.

    Science.gov (United States)

    Yang, Di; Okamura, Hirohiko; Teramachi, Jumpei; Haneji, Tatsuji

    2016-04-01

    Posttranslational modifications including histone methylation regulate gene transcription through directly affecting the structure of chromatin. Trimethylation of histone H3K27 (H3K27me3) contributes to gene silencing and the histone demethylase Jumonji domain-containing 3 (Jmjd3) specifically removes the methylation of H3K27me3, followed by the activation of gene expression. In the present study, we explored the roles of Jmjd3 in regulating osteoblast apoptosis. Knockdown of Jmjd3 promoted osteoblast apoptosis induced by serum deprivation with decreased mitochondrial membrane potential and increased levels of caspase-3 activation, PARP cleavage, and DNA fragmentation. B cell lymphoma-2 (Bcl-2), an anti-apoptotic protein, was down-regulated by knockdown of Jmjd3 through retaining H3K27me3 on its promoter region. Knockdown of Jmjd3 increased the pro-apoptotic activity of Bim through inhibiting ERK-dependent phosphorylation of Bim. Protein kinase D1 (PKD1), which stimulates ERK phosphorylation, decreased in the Jmjd3-knockdown cells and introduction of PKD1 relieved osteoblast apoptosis in the Jmjd3-knockdown cells through increasing ERK-regulated Bim phosphorylation. These results suggest that Jmjd3 regulates osteoblast apoptosis through targeting Bcl-2 expression and Bim phosphorylation. PMID:26795455

  20. Expression of Bcl-2 inhibited Fas-mediated apoptosis in human hepatocellular carcinoma BEL-7404 cells

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Apoptosis plays an important role in embryonic development, tissue remodeling, immune regulation and tumor regression. Two groups of molecules (Bcl-2 family and"Death factor"family) are involved in regulating apoptosis. In order to know about the effect of Bcl-2 on apoptosis induced by Fas, a typical member of"Death factor" family, the transfection experiments with expression vectors pcDNA3-fland pcDNA3-bcl-2 were performed in BEL-7404 cells, a human hepatocellular carcinoma cell line which expresses endogenous Fas, but not FasL and Bcl2. The data showed that the expression of FasL in pcDNA3fl transfected hepatoma cells obviously induced the apoptosis of the cells. However, the overexpression of Bcl-2 in pcDNA3bcl-2 transfected 7404/b-16 cells counteracted pcDNA3-fltransient transfection mediated apoptosis. Further study by cotransfection experiments indicated that Bid but not Bax (both were pro-apoptotic proteins of Bcl-2 family) blocked the inhibitory effect of Bcl-2 on Fas-mediated apoptosis. These results suggested that Fas-mediated apoptosis in human hcpatoma cells is possibly regulated by Bcl-2 family proteins via mitochondria pathway.

  1. Expression of protein encoded by apoptosis-associated gene p53, bcl-2, and bax in adaptive response of thymocyte apoptosis in mice induced by low dose radiation with X-rays

    International Nuclear Information System (INIS)

    Objective: To explore the regulative mechanism of apoptosis-associated gene proteins on the adaptive response of thymocyte apoptosis in mice induced by low dose radiation with X-rays. Methods: Kunming male mice were irradiated with the inductive doses (D1: 25, 50, 75, 100 and 200 mGy; dose rate: 12.5 mGy ·min-1) and the challenging dose (D2: 1.5 Gy; dose rate: 287 mGy·min-1). The time interval between D1 and D2 was 6 h. The expressive levels of thymocyte apoptosis-associated gene proteins were measured with flow cytometry. Results: As compared with the sham-irradiation, the positive percentage of thymocyte Bcl-2 protein expression decreased significantly in D2 group (P<0.05), Bax increased significantly (P<0.05), and Bcl-2/Bax decreased significantly (P<0.001); p 53 increased significantly (P<0.001). As compared with D2 group, the positive percentage of thymocyte Bcl-2 protein expression increased in varying degree in D1+ D2 group of 25-75 mGy D1, Bax decreased in varying degree, and Bcl-2/Bax increased significantly (P<0.01); p53 decreased significantly (P<0.001 or P<0.05). Conclusion: The apoptotic thymocytes in the adaptive response of thymocyte apoptosis in mice induced by irradiation with 25-75 mGy decrease significantly due to the increase of apoptosis-associated gene Bcl-2 protein expression and Bcl-2/Bax, the decrease of Bax and p53 protein expressions. (authors)

  2. PI3K inhibitors prime neuroblastoma cells for chemotherapy by shifting the balance towards pro-apoptotic Bcl-2 proteins and enhanced mitochondrial apoptosis.

    Science.gov (United States)

    Bender, A; Opel, D; Naumann, I; Kappler, R; Friedman, L; von Schweinitz, D; Debatin, K-M; Fulda, S

    2011-01-27

    We recently identified activation of phosphatidylinositol 3'-kinase (PI3K)/Akt as a novel predictor of poor outcome in neuroblastoma. Here, we investigated the effect of small-molecule PI3K inhibitors on chemosensitivity. We provide first evidence that PI3K inhibitors, for example PI103, synergize with various chemotherapeutics (Doxorubicin, Etoposide, Topotecan, Cisplatin, Vincristine and Taxol) to trigger apoptosis in neuroblastoma cells (combination index: high synergy). Mechanistic studies reveal that PI103 cooperates with Doxorubicin to reduce Mcl-1 expression and Bim(EL) phosphorylation and to upregulate Noxa and Bim(EL) levels. This shifted ratio of pro- and antiapoptotic Bcl-2 proteins results in increased Bax/Bak conformational change, loss of mitochondrial membrane potential, cytochrome c release, caspase activation and caspase-dependent apoptosis. Although Mcl-1 knockdown enhances Doxorubicin- and PI103-induced apoptosis, silencing of Noxa, Bax/Bak or p53 reduces apoptosis, underscoring the functional relevance of the Doxorubicin- and PI103-mediated modulation of these proteins for chemosensitization. Bcl-2 overexpression inhibits Bax activation, mitochondrial perturbations, cleavage of caspases and Bid, and apoptosis, confirming the central role of the mitochondrial pathway for chemosensitization. Interestingly, the broad-range caspase inhibitor zVAD.fmk does not interfere with Bax activation or mitochondrial outer membrane permeabilization, whereas it blocks caspase activation and apoptosis, thus placing mitochondrial events upstream of caspase activation. Importantly, PI103 and Doxorubicin cooperate to induce apoptosis and to suppress tumor growth in patients' derived primary neuroblastoma cells and in an in vivo neuroblastoma model, underlining the clinical relevance of the results. Thus, targeting PI3K presents a novel and promising strategy to sensitize neuroblastoma cells for chemotherapy-induced apoptosis, which has important implications for the

  3. Prognostic Significance of Apoptosis Related Gene Family bcl-2 in Human Breast Cancer

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    To study the prognostic effect of bcl-2 oncogene and its gene family members bax, bcl-x expression in breast cancer patients. Methods: expression of bcl-2, bax proteins in 91 human breast cancer tissue sections were studied by immunohistochemical method. Bcl-x1 mRNA expression in frozen tissues from 16 breast cancer patients were detected using Northern blot method. Results: bcl-2 protein positivity was found in 60/91 (65.9%) patients, and bax positivity 59/91 (64.8%). Bcl-2 and bax expression levels were associated with apoptotic index(AI), histological grade, axillary lymph node metastasis, postoperative local recurrence and metastasis. Bcl-2 expression was related to ER positivity. In univariate analysis for disease free survival (DFS), bcl-2 and bax protein levels, and Al were all found to have prognostic value. The result of Cox's model multivariate analysis showed that bcl-2 protein level was an independent prognostic factor. In 16 frozen breast cancer tissues, 8/16(50%) had higher level of bcl-x1 mRNA, which showed correlation with bcl-2 protein expression and axillary lymph node metastasis. Conclusion: The findings indicate that dysregulated expressions of bcl-2, bax and bcl-x1 apoptosis-related genes, suggestive of serious deregulation of apoptotic process, may contribute to the biologic aggressiveness of breast cancer. Bcl-2 protein is an independent indicator of prognosis in breast cancer patients.

  4. Cytotoxicity of carteolol to human corneal epithelial cells by inducing apoptosis via triggering the Bcl-2 family protein-mediated mitochondrial pro-apoptotic pathway.

    Science.gov (United States)

    Shan, Ming; Fan, Ting-Jun

    2016-09-01

    Carteolol is a frequently used nonselective β-adrenoceptor antagonist for glaucoma and ocular hypertension treatment, and its repeated/prolonged usage might be cytotoxic to the cornea, especially the outmost human corneal epithelium (HCEP). The aim of the present study was to characterize the cytotoxicity of carteolol to HCEP and its underlying cellular and molecular mechanisms using an in vitro model of HCEP cells. After HCEP cells were treated with carteolol at concentrations varying from 2% to 0.015625%, the cytotoxicity, apoptosis-inducing effect and pro-apoptotic pathway was investigated, respectively. Our results showed that carteolol at concentrations above 0.03125% induced time- and dose-dependent growth retardation, cytopathic morphological changes and viability decline of HCEP cells. Moreover, carteolol induced G1 phase arrest, plasma membrane permeability elevation, phosphatidylserine externalization, DNA fragmentation, and apoptotic body formation of HCEP cells. Furthermore, carteolol also induced activation of caspase-9 and -3, disruption of mitochondrial transmembrane potential, up-regulation the cytoplasmic amount of cytochrome c and apoptosis-inducing factor, and up-regulation of pro-apoptotic Bax and Bad, down-regulation of anti-apoptotic Bcl-2 and Bcl-xL. In conclusion, carteolol above 1/64 of its clinical therapeutic dosage has a time- and dose-dependent cytotoxicity to HCEP cells, which is achieved by inducing apoptosis via triggering Bcl-2 family protein-mediated mitochondrial pro-apoptotic pathway. PMID:27216471

  5. BEX1 promotes imatinib-induced apoptosis by binding to and antagonizing BCL-2.

    Directory of Open Access Journals (Sweden)

    Qian Xiao

    Full Text Available An enhanced anti-apoptotic capacity of tumor cells plays an important role in the process of breakpoint cluster region/Abelson tyrosine kinase gene (BCR/ABL-independent imatinib resistance. We have previously demonstrated that brain expressed X-linked 1 (BEX1 was silenced in secondary imatinib-resistant K562 cells and that re-expression of BEX1 can restore imatinib sensitivity resulting in the induction of apoptosis. However, the mechanism by which BEX1 executes its pro-apoptotic function remains unknown. We identified B-cell lymphoma 2 (BCL-2 as a BEX1-interacting protein using a yeast two-hybrid screen. The interaction between BEX1 and BCL-2 was subsequently confirmed by co-immunoprecipitation assays. Like BCL-2, BEX1 was localized to the mitochondria. The region between 33K and 64Q on BEX1 is important for its localization to the mitochondria and its ability to interact with BCL-2. Additionally, we found that this region is essential for BEX1-regulated imatinib-induced apoptosis. Furthermore, we demonstrated that the interaction between BCL-2 and BEX1 promotes imatinib-induced apoptosis by suppressing the formation of anti-apoptotic BCL-2/BCL-2-associated X protein (BAX heterodimers. Our results revealed an interaction between BEX1 and BCL-2 and a novel mechanism of imatinib resistance mediated by the BEX1/BCL-2 pathway.

  6. Overexpression of Bcl2 in osteoblasts inhibits osteoblast differentiation and induces osteocyte apoptosis.

    Directory of Open Access Journals (Sweden)

    Takeshi Moriishi

    Full Text Available Bcl2 subfamily proteins, including Bcl2 and Bcl-X(L, inhibit apoptosis. As osteoblast apoptosis is in part responsible for osteoporosis in sex steroid deficiency, glucocorticoid excess, and aging, bone loss might be inhibited by the upregulation of Bcl2; however, the effects of Bcl2 overexpression on osteoblast differentiation and bone development and maintenance have not been fully investigated. To investigate these issues, we established two lines of osteoblast-specific BCL2 transgenic mice. In BCL2 transgenic mice, bone volume was increased at 6 weeks of age but not at 10 weeks of age compared with wild-type mice. The numbers of osteoblasts and osteocytes increased, but osteoid thickness and the bone formation rate were reduced in BCL2 transgenic mice with high expression at 10 weeks of age. The number of BrdU-positive cells was increased but that of TUNEL-positive cells was unaltered at 2 and 6 weeks of age. Osteoblast differentiation was inhibited, as shown by reduced Col1a1 and osteocalcin expression. Osteoblast differentiation of calvarial cells from BCL2 transgenic mice also fell in vitro. Overexpression of BCL2 in primary osteoblasts had no effect on osteoclastogenesis in co-culture with bone marrow cells. Unexpectedly, overexpression of BCL2 in osteoblasts eventually caused osteocyte apoptosis. Osteocytes, which had a reduced number of processes, gradually died with apoptotic structural alterations and the expression of apoptosis-related molecules, and dead osteocytes accumulated in cortical bone. These findings indicate that overexpression of BCL2 in osteoblasts inhibits osteoblast differentiation, reduces osteocyte processes, and causes osteocyte apoptosis.

  7. BCL-2 family proteins as regulators of mitochondria metabolism.

    Science.gov (United States)

    Gross, Atan

    2016-08-01

    The BCL-2 family proteins are major regulators of apoptosis, and one of their major sites of action are the mitochondria. Mitochondria are the cellular hubs for metabolism and indeed selected BCL-2 family proteins also possess roles related to mitochondria metabolism and dynamics. Here we discuss the link between mitochondrial metabolism/dynamics and the fate of stem cells, with an emphasis on the role of the BID-MTCH2 pair in regulating this link. We also discuss the possibility that BCL-2 family proteins act as metabolic sensors/messengers coming on and off of mitochondria to "sample" the cytosol and provide the mitochondria with up-to-date metabolic information. This article is part of a Special Issue entitled 'EBEC 2016: 19th European Bioenergetics Conference, Riva del Garda, Italy, July 2-6, 2016', edited by Prof. Paolo Bernardi. PMID:26827940

  8. Statins, Bcl-2 and Apoptosis: Cell Death or Cell Protection?

    OpenAIRE

    Wood, W. Gibson; Igbavboa, Urule; Muller, Walter E.; Gunter P. Eckert

    2013-01-01

    Statins have proven their effectiveness in the treatment of cardiovascular disease. This class of drugs has also attracted attention as a potential treatment for dissimilar diseases such as certain types of cancers and neurodegenerative diseases. What appears to be a contradiction is that in the case of cancer, it has been suggested that statins increase apoptosis and alter levels of Bcl-2 family members (e.g., reduce Bcl-2 and increase Bax) whereas, studies mainly using non-cancerous cells r...

  9. MicroRNA-125b Induces Cancer Cell Apoptosis Through Suppression of Bcl-2 Expression

    Institute of Scientific and Technical Information of China (English)

    Aihua Zhao; Quan Zeng; Xiaoyan Xie; unnian Zhou; Wen Yue; Yali Li; Xuetao Pei

    2012-01-01

    MicroRNAs (miRNAs) are small,noncoding RNAs which can often act as an oncogene or a tumor suppressor.Several miRNAs are associated with the development of hepatocellular carcinoma (HCC).We demonstrated that miR-125b significantly suppresses HCC cell proliferation and promotes apoptosis by inhibiting the gene expression of the anti-apoptotic protein,Bcl-2.Bioinformatic analysis indicated that the 3'UTR of Bcl-2 has binding sites for miR-125b.Luciferase reporter assay confirmed the ability of miR-125b to dramatically suppress Bcl-2 transcription,suggesting that Bcl-2 is a target gene for miR-125b.We concluded that miR-125b acts as a tumor suppressor in hepatic tumor development by targeting Bcl-2 and inducing cancer cell apoptosis.

  10. Overexpression of the hydatidiform mole-related gene F10 inhibits apoptosis in A549 cells through downregulation of BCL2-associated X protein and caspase-3.

    Science.gov (United States)

    Song, Yali; Zhang, Gong; Zhu, Xiulan; Pang, Zhanjun; Xing, Fuqi; Quan, Song

    2012-09-01

    The aim of this study was to investigate how the overexpression of the hydatidiform mole-related gene F10 affects apoptosis in human lung cancer A549 cells. A549 cells were transfected with pEGFP-N1-F10 (A549-F10) or pEGFP-N1 empty vector (A549-empty). Untransfected A549, A549-F10 or A549-empty cells were examined using the MTT cell proliferation assay and the TUNEL-FITC/Hoechst 33258 apoptosis assay. Western blotting was used to examine the expression levels of the pro-apoptotic genes, BCL2-associated X protein (BAX) and caspase-3. F10 was stably expressed in A549 cells. From 12 h, A549-F10 cells proliferated markedly faster than the untransfected and A549-empty cells. F10 overexpression also significantly inhibited apoptosis, as shown by the reduced number of TUNEL and Hoechst 33258 double-positive cells. This inhibition was likely due to an F10-induced reduction in the BAX and caspase-3 levels. The results of this study indicate that F10 overexpression inhibits apoptosis in A549 cells through the downregulation of the pro-apoptotic genes BAX and caspase-3. PMID:23741243

  11. The influence of sleep deprivation on expression of apoptosis regulatory proteins p53, bcl-2 and bax following rat tongue carcinogenesis induced by 4-nitroquinoline 1-oxide

    Directory of Open Access Journals (Sweden)

    Juliana Noguti

    2013-01-01

    Full Text Available Background: The aim of this study was to evaluate whether paradoxical sleep deprivation could affects the mechanisms and pathways essentials for cancer cells in tongue cancer induced by 4-nitroquinole 1-oxide in Wistar rats. Materials and Methods: For this purpose, the animals were distributed into 4 groups of 5 animals each treated with 50 ppm 4 nitroquinoline 1 oxide (4 NQO solution through their drinking water for 4 and 12 weeks. The animals were submitted to paradoxical sleep deprivation (PSD for 72 h using the modified multiple platform method, which consisted of placing 5 mice in a cage (41 × 34 × 16 cm containing 10 circular platforms (3.5 cm in diameter with water 1 cm below the upper surface. The investigations were conducted using immunohistochemistry of p53, Bax and Bcl-2 proteins related to apoptosis and its pathways. Statistical analysis was performed by Kruskal-Wallis non-parametric test followed by the Dunn′s test using SPSS software pack (version 1.0. P value < 0.05 was considered for statistic significance. Results: Although no histopathological abnormalities were induced in the epithelium after 4 weeks of carcinogen exposure in all groups, in 12 weeks were observed pre-neoplasic lesions. Data analysis revealed statistically significant differences ( P < 0.05 in 4 weeks group for p53 and for bcl-2 and for all immunomarkers after 12 weeks of 4NQO administration. Conclusion: Our results reveal that sleep deprivation exerted alterations in proteins associated with proliferation and apoptosis in carcinogenesis.

  12. Labdane type diterpenes down-regulate the expression of c-Myc protein, but not of Bcl-2, in human leukemia T-cells undergoing apoptosis.

    Science.gov (United States)

    Dimas, K; Demetzos, C; Vaos, V; Ioannidis, P; Trangas, T

    2001-06-01

    Sclareol (1) and ent-3beta-hydroxy-13-epi-manoyl oxide (2) belong to the labdane type diterpenes. They were isolated from the leaves and from the fruits of Cistus creticus subsp. creticus, and were found to be active against human leukemic cell lines. Compound 2 was converted to its thiomidazolide derivative (3). Compounds 1 and 3 were found to induce apoptotic cell death in human T-cell leukemia lines and to interfere with their cell cycle, arresting cells at G(0/1) phase. Apoptosis can involve the activation and/or suppression of critical genes such as c-myc whose reduction or its inappropriate expression can be associated with induction of cell death and bcl-2 whose activation prevents apoptosis in the latter case. In order to detect any concomitant effect (1 and 3) upon c-myc and bcl-2 oncogene expression, we performed Western blot analysis to determine the levels of expression of these two genes upon treatment with the above compounds. Western blot analysis showed that of c-myc proto-oncogene levels were markedly reduced before massive apoptosis ensued in H33AJ-JA1 and MOLT3 cells, while bcl-2 expression remained unaffected. Thus, induction of apoptosis due to compounds 1 and 3 in these T-cell leukemic cell lines is preceded by c-myc down regulation and furthermore sustained bcl-2 expression does not rescue cells from apoptosis under the conditions used. PMID:11337016

  13. Structural and functional similarity between the bacterial type III secretion system needle protein PrgI and the eukaryotic apoptosis Bcl-2 proteins.

    Directory of Open Access Journals (Sweden)

    Matthew D Shortridge

    Full Text Available BACKGROUND: Functional similarity is challenging to identify when global sequence and structure similarity is low. Active-sites or functionally relevant regions are evolutionarily more stable relative to the remainder of a protein structure and provide an alternative means to identify potential functional similarity between proteins. We recently developed the FAST-NMR methodology to discover biochemical functions or functional hypotheses of proteins of unknown function by experimentally identifying ligand binding sites. FAST-NMR utilizes our CPASS software and database to assign a function based on a similarity in the structure and sequence of ligand binding sites between proteins of known and unknown function. METHODOLOGY/PRINCIPAL FINDINGS: The PrgI protein from Salmonella typhimurium forms the needle complex in the type III secretion system (T3SS. A FAST-NMR screen identified a similarity between the ligand binding sites of PrgI and the Bcl-2 apoptosis protein Bcl-xL. These ligand binding sites correlate with known protein-protein binding interfaces required for oligomerization. Both proteins form membrane pores through this oligomerization to release effector proteins to stimulate cell death. Structural analysis indicates an overlap between the PrgI structure and the pore forming motif of Bcl-xL. A sequence alignment indicates conservation between the PrgI and Bcl-xL ligand binding sites and pore formation regions. This active-site similarity was then used to verify that chelerythrine, a known Bcl-xL inhibitor, also binds PrgI. CONCLUSIONS/SIGNIFICANCE: A structural and functional relationship between the bacterial T3SS and eukaryotic apoptosis was identified using our FAST-NMR ligand affinity screen in combination with a bioinformatic analysis based on our CPASS program. A similarity between PrgI and Bcl-xL is not readily apparent using traditional global sequence and structure analysis, but was only identified because of conservation in

  14. BH4 domain of bcl-2 protein is required for its proangiogenic function under hypoxic condition.

    Science.gov (United States)

    Gabellini, Chiara; De Luca, Teresa; Trisciuoglio, Daniela; Desideri, Marianna; Di Martile, Marta; Passeri, Daniela; Candiloro, Antonio; Biffoni, Mauro; Rizzo, Maria Giulia; Orlandi, Augusto; Del Bufalo, Donatella

    2013-11-01

    Beyond its classical role as apoptosis inhibitor, bcl-2 protein promotes tumor angiogenesis and the removal of N-terminal bcl-2 homology (BH4) domain abrogates bcl-2-induced hypoxia-inducible factor 1 (HIF-1)-mediated vascular endothelial growth factor (VEGF) expression in hypoxic cancer cells. Using M14 human melanoma cell line and its derivative clones stably overexpressing bcl-2 wild-type or deleted of its BH4 domain, we found that conditioned media (CM) from cells expressing BH4-deleted bcl-2 protein showed a reduced capability to increase in vitro human endothelial cells proliferation and differentiation, and in vivo neovascularization compared with CM from cells overexpressing wild-type bcl-2. Moreover, xenografts derived from cells expressing bcl-2 lacking BH4 domain showed a reduction of metastatic potential compared with tumors derived from wild-type bcl-2 transfectants injection. Stably expressing the Flag-tagged N-terminal sequence of bcl-2 protein, encompassing BH4 domain, we found that this domain is sufficient to enhance the proangiogenic HIF-1/VEGF axis under hypoxic condition. Indeed, lacking of BH4 domain abolishes the interaction between bcl-2 and HIF-1α proteins and the capability of exogenous bcl-2 protein to localize in the nucleus. Moreover, when endoplasmic reticulum-targeted bcl-2 protein is overexpressed in cells, this protein lost the capability to synergize with hypoxia to induce the proangiogenic HIF-1/VEGF axis as shown by wild-type bcl-2 protein. These results demonstrate that BH4 domain of bcl-2 is required for the ability of this protein to increase tumor angiogenesis and progression and indicate that bcl-2 nuclear localization may be required for bcl-2-mediated induction of HIF-1/VEGF axis. PMID:23836782

  15. Effect of Bcl-2 and caspase-3 on calcium distribution in apoptosis of HL-60 cells

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Apoptosis manifests in two major execution programs downstream of the death signal: the caspase pathway and organelle dysfunction. An important antiapoptosis factor, Bcl-2 protein, contributes in caspase pathway of apoptosis. Calcium, an important intracellular signal element in cells, is also observed to have changes during apoptosis, which maybe affected by Bcl2 protein. We have previously reported that in Harringtonine (HT) induced apoptosis of HL-60 cells, there's a change of intracellular calcium distribution, moving from cytoplast especially Golgi's apparatus to nucleus and accumulating there with the highest concentration. We report here that caspase-3 becomes activated in HT-induced apoptosis of HL-60 cells, which can be inhibited by overexpression of Bcl-2 protein. No sign of apoptosis or intracellular calcium movement from Golgi's apparatus to nucleus in HL-60 cells overexpressing Bcl-2 or treated with Ac-DEVD-CHO, a specific inhibitor of caspase-3. The results indicate that activated caspase-3 can promote the movement of intracellular calcium from Golgi's apparatus to nucleus, and the process is inhibited by Ac-DEVD-CHO (inhibitor of caspas-3), and that Bcl-2 can inhibit the movement and accumulation of intracellular calcium in nucleus through its inhibition on caspase3. Calcium relocalization in apoptosis seems to be irreversible, which is different from the intracellular calcium changes caused by growth factor.

  16. Enhancement of bcl-2 antisense oligodeoxynucleotide on γ-ray induced-apoptosis in malignant lymphoma cells

    International Nuclear Information System (INIS)

    Objective: To investigate whether bcl-2 antisense oligodeoxynucleotide (ASODN) could enhance 60Co γ-ray induced-apoptosis in malignant lymphoma cells. Methods: Cell apoptosis situation, cellular DNA contents and bcl-2 protein expression were determined by cell stain, TdT-mediated dUTP Nick-end Labeling (TUNEL) and flow cytometry. Results: One to 8 Gy γ-ray and 10-40 μmol/L bcl-2 ASODN could inhibit Raji cell growth and induce cell apoptosis. Assay of flow cytometry showed that the number of Sub-G1 cells was significantly increased and Bcl-2 protein expression in Raji cells was significantly downregulated, which showed time- and dose-dependent manners. The effects were more pronounced when γ-ray and bcl-2 ASODN were used together rather than either alone. Conclusion: Bcl-2 antisense oligodeoxynucleotide could enhance 60Co γ-ray induced-apoptosis in malignant lymphoma cells. (authors)

  17. Epstein-Barr virus interactions with the Bcl-2 protein family and apoptosis in human tumor cells

    Institute of Scientific and Technical Information of China (English)

    Qin FU; Chen HE; Zheng-rong MAO

    2013-01-01

    Epstein-Barr virus (EBV),a human gammaherpesvirus carried by more than 90% of the world's population,is associated with malignant tumors such as Burkitt's lymphoma (BL),Hodgkin lymphoma,post-transplant lymphoma,extra-nodal natural killer/T cell lymphoma,and nasopharyngeal and gastric carcinomas in immune-compromised patients.In the process of infection,EBV faces challenges:the host cell environment is harsh,and the survival and apoptosis of host cells are precisely regulated.Only when host cells receive sufficient survival signals may they immortalize.To establish efficiently a lytic or long-term latent infection,EBV must escape the host cell immunologic mechanism and resist host cell apoptosis by interfering with multiple signaling pathways.This review details the apoptotic pathway disrupted by EBV in EBV-infected cells and describes the interactions of EBV gene products with host cellular factors as well as the function of these factors,which decide the fate of the host cell.The relationships between other EBV-encoded genes and proteins of the B-cell leukemia/lymphoma (Bcl) family are unknown.Still,EBV seems to contribute to establishing its own latency and the formation of tumors by modifying events that impact cell survival and proliferation as well as the immune response of the infected host.We discuss potential therapeutic drugs to provide a foundation for further studies of tumor pathogenesis aimed at exploiting novel therapeutic strategies for EBV-associated diseases.

  18. Synergistic antitumoral activity and induction of apoptosis by novel pan Bcl-2 proteins inhibitor apogossypolone with adriamycin in human hepatocellular carcinoma

    Institute of Scientific and Technical Information of China (English)

    Jin-xia MI; Guang-feng WANG; Heng-bang WANG; Xiao-qing SUN; Xin-yan NI; Xiong-wen ZHANG; Jia-ming TANG; Da-jun YANG

    2008-01-01

    Aim: To investigate the in vitro and in vivo activities and related mechanism of apogossypoione (ApoG2) alone or in combination with adriamycin (ADM) against human hepatocellular carcinoma (HCC). Methods: The IC50 of ApoG2 in vitro was tested by WST assay, and the synergistic effect was analyzed using the CalcuSyn method. Cell apoptosis was determined using 4',6-diamidino-2-phenylindole staining and flow cytometric analysis. Western blotting was used to determine the expression of apoptosis-related proteins. In vivo activity was evaluated in the xenograft model in nude mice, and apoptosis in tumor tissues was determined by terminal deoxynucleotidyl transferase-mediated digoxigenin-dUTP nick-end labeling (TUNEL) assay. Results: The IC50 of ApoG2 in HCC cells was 17.28-30.63 μmol/L. When ApoG2 was combined with ADM, in-creased cytotoxicity and apoptosis were observed in SMMC-7721 cells compared to treatment with ApoG2 alone. The Western blotting results indicated that the ApoG2 induced apoptosis in SMMC-7721 cells by downregulating anti-apoptotic proteins Bcl-2, Mcl-1, and Bcl-XL, up-regulating pro-apoptotic protein Noxa, and promoting the activities of caspases-9 and -3. The tumor growth of xenograft SMMC-7721 was inhibited in nude mice when ApoG2 was administered orally without causing damage to the normal tissues. The in vivo study also indicated an increasing anti-tumoral effect when ApoG2 at 100 or 200 mg/kg dosages were used together with ADM at 5.5 mg/kg, with relative tumor proliferation rate (T/C) values of 0.456 and 0.323, respectively. Apoptosis induced in vivo by ApoG2 alone or combined with ADM was confirmed by TUNEL assay in tumor tissues. Conclusion: ApoG2 is a potential non-toxic target agent that induces apoptosis by upregulating Noxa, while inhibiting anti-apoptotic proteins and pro-moting the effect of chemotherapy agent ADM in HCC.

  19. Study of immunohistochemical demonstration of Bcl-2 protein in ameloblastoma and keratocystic odontogenic tumor

    OpenAIRE

    C S Sindura; Chaitanya Babu; Vijaya Mysorekar; Vinod Kumar

    2013-01-01

    Background: The Bcl-2 (B-cell lymphoma) gene product also known as apoptotic inhibitor is expressed in many normal and tumor tissues. This Bcl-2 gene protects the cell by blocking postmitotic differentiation from apoptosis, thus maintaining the stem cell pool. Objective: To study the expression of Bcl-2 protein in ameloblastoma and keratocystic odontogenic tumor (KCOT) to determine their apoptotic behaviors and to analyze biological nature of KCOT, which has higher proliferative potential and...

  20. The Role of Bcl-2 Family Proteins in Therapy Responses of Malignant Astrocytic Gliomas: Bcl2L12 and Beyond

    Directory of Open Access Journals (Sweden)

    Fotini M. Kouri

    2012-01-01

    Full Text Available Glioblastoma (GBM is a highly aggressive and lethal brain cancer with a median survival of less than two years after diagnosis. Hallmarks of GBM tumors include soaring proliferative indices, high levels of angiogenesis, diffuse invasion into normal brain parenchyma, resistance toward therapy-induced apoptosis, and pseudopallisading necrosis. Despite the recent advances in neurosurgery, radiation therapy, and the development of targeted chemotherapeutic regimes, GBM remains one of the deadliest types of cancer. Particularly, the alkylating agent temozolomide (TMZ in combination with radiation therapy prolonged patient survival only marginally, and clinical studies assessing efficacies of targeted therapies, foremost ATP mimetics inhibiting the activity of receptor tyrosine kinases (RTKs, revealed only few initial responders; tumor recurrence is nearly universal, and salvage therapies to combat such progression remain ineffective. Consequently, myriad preclinical and clinical studies began to define the molecular mechanisms underlying therapy resistance of GBM tumors, and pointed to the Bcl-2 protein family, in particular the atypical member Bcl2-Like 12 (Bcl2L12, as important regulators of therapy-induced cell death. This review will discuss the multi-faceted modi operandi of Bcl-2 family proteins, describe their roles in therapy resistance of malignant glioma, and outline current and future drug development efforts to therapeutically target Bcl-2 proteins.

  1. Biphasic onset of splenic apoptosis following hemorrhagic shock : critical implications for Bax, Bcl-2, and Mcl-1 proteins

    OpenAIRE

    Hostmann, Arwed; Jasse, Kerstin; Schulze-Tanzil, Gundula; Robinson, Yohan; Oberholzer, Andreas; Ertel, Wolfgang; Tschoeke, Sven K

    2008-01-01

    INTRODUCTION: The innate immune response to trauma hemorrhage involves inflammatory mediators, thus promoting cellular dysfunction as well as cell death in diverse tissues. These effects ultimately bear the risk of post-traumatic complications such as organ dysfunction, multiple organ failure, or adult respiratory distress syndrome. In this study, a murine model of resuscitated hemorrhagic shock (HS) was used to determine the apoptosis in spleen as a marker of cellular injury and reduced immu...

  2. Therapeutic Modulation of Apoptosis: Targeting the BCL-2 Family at the Interface of the Mitochondrial Membrane

    Science.gov (United States)

    Nemec, Kathleen N.

    2008-01-01

    A vast portion of human disease results when the process of apoptosis is defective. Disorders resulting from inappropriate cell death range from autoimmune and neurodegenerative conditions to heart disease. Conversely, prevention of apoptosis is the hallmark of cancer and confounds the efficacy of cancer therapeutics. In the search for optimal targets that would enable the control of apoptosis, members of the BCL-2 family of anti- and pro-apoptotic factors have figured prominently. Development of BCL-2 antisense approaches, small molecules, and BH3 peptidomimetics has met with both success and failure. Success-because BCL-2 proteins play essential roles in apoptosis. Failure-because single targets for drug development have limited scope. By examining the activity of the BCL-2 proteins in relation to the mitochondrial landscape and drawing attention to the significant mitochondrial membrane alterations that ensue during apoptosis, we demonstrate the need for a broader based multi-disciplinary approach for the design of novel apoptosis-modulating compounds in the treatment of human disease. PMID:18972587

  3. THE EXPRESSION AND CLINICAL VALUE OF APOPTOSIS CONTROL GENE Bcl-2 AND Bax IN BREAST CANCER

    Institute of Scientific and Technical Information of China (English)

    ZHENG Jun; YAO Zhen-xiang; ZHANG Jing

    1999-01-01

    Objective: To study the expression and clinical value of apoptosis control gene bcl-2 and bax in breast cancer.Methods: Protein bax and bcl-2 in 41 breast cancers obtained from operations in our hospital in 1996 were detected using ABC immunohistochemical stain assay and compared with 10 cases with normal breast tissues.Results: The positive rate of bax in normal breast tissue was 90% and in breast cancer was 59%, with a significant statistical difference between them (P<0.05), but there was no statistical difference in bcl-2 protein expression. Among the 41 breast cancer, the group with lymph node metastasis (21 cases) had obviously low bax expression (43%) and high bcl-2 expression (76%), showing significant difference to the group without lymph node metastasis (P<0.05).Conclusion: The antiapoptosis function of bcl-2 was stronger than bax in breast cancer. Protein bax and bcl-2 assay may be useful in understanding the biological behaviors of breast cancer.

  4. [Bcl-2 inhibits p53-induced apoptosis after genotoxic damage by inhibitors of nuclear import of p53].

    Science.gov (United States)

    Beham, A; Schumacher, G; McDonnell, T J; Marin, M C; Jauch, K W

    1998-01-01

    The tumor suppressor gene p53 in overexpressed in 50% of colorectal carcinomas and is an interesting target for gene therapeutic approaches. Furthermore the protooncogen bcl-2 is known to inhibit p53 induced apoptosis and is expressed in some colorectal carcinomas. In this study mechanism of bcl-2 cell death inhibition after p53 induction were evaluated. The human colon carcinoma cell line RKO posses wild-type p53 and also expresses bcl-2 protein. RKO cells were treated with liposomal bcl-2 antisense oligonucleotides (AS), control oligonucleotides (CO) and empty liposomes (EL) resulting in decreased bcl-2 expression. After induction of p53 with gamma-irradiation p53 protein expression was induced in AS, CO and EL pretreated cells. Microscopy and immunoblotting was used to characterize subcellular localization of p53 protein. Further p53 subcellular localisation was examined after p53 transfer of wt p53 cDNA in three bcl-2 expressing cell lines. Most of the p53 protein remained localized in the cytosol and apoptosis was decreased in bcl-2 expressing cells assessed by flow cytometric analysis (Ao). Our data suggests that bcl-2 is able to modulate transmembrane trafficking of p53. This resulted in inhibition of cell death implicating that bcl-2 function is involved in regulation of transmembrane gradients. PMID:14518224

  5. BRCA1 involved in regulation of Bcl-2 expression and apoptosis susceptibility to ionizing radiation

    Science.gov (United States)

    Wang, YanLing; Wang, Bing; Zhang, Hong; Li, Ning; Tanaka, Kaoru; Zhou, Xin; Chen, RuPing; Zhang, Xin

    2011-05-01

    BRCA1 has been proposed to be tightly linked to the resistance of tumor cells to ionizing radiation. The pathway leading to this phenomenon is not yet clear. In this work, we investigated the role of BRCA1 in the apoptosis regulation in response to carbon ion irradiation. We utilized three different cancer cell lines with various states for BRCA1 and p53 to identify the relationship between endogenous BRCA1 and the apoptosis-related genes, and determine whether p53 function would affect the role of BRCA1 in apoptosis regulation. By Western blot analysis, we found that Bax expressions were not significantly changed after irradiation in all of three cell lines. However, Bcl-2 expression showed an up-regulation by endogenous BRCA1 regardless of p53 status. Moreover, the changes in Bcl-2 protein were due to the increase in the transcriptional levels of Bcl-2 mRNA, based on real-time PCR assay. At the same time, BRCA1-deficient cells showed a greater apoptosis susceptibility to irradiation when compared with BRCA1-proficient cells. The results suggest that BRCA1 might exert p53-independent regulative activities for Bcl-2, which seems account for the low apoptosis susceptibility in BRCA1-proficient carcinomas.

  6. Quantification of protein copy number in single mitochondria: The Bcl-2 family proteins.

    Science.gov (United States)

    Chen, Chaoxiang; Zhang, Xiang; Zhang, Shuyue; Zhu, Shaobin; Xu, Jingyi; Zheng, Yan; Han, Jinyan; Zeng, Jin-Zhang; Yan, Xiaomei

    2015-12-15

    Bcl-2 family proteins, represented by antiapoptotic protein Bcl-2 and proapoptotic protein Bax, are key regulators of mitochondria-mediated apoptosis pathway. To build a quantitative model of how Bcl-2 family protein interactions control mitochondrial outer membrane permeabilization and subsequent cytochrome c release, it is essential to know the number of proteins in individual mitochondria. Here, we report an effective method to quantify the copy number and distribution of proteins in single mitochondria via immunofluorescent labeling and sensitive detection by a laboratory-built high sensitivity flow cytometer (HSFCM). Mitochondria isolated from HeLa cells were stained with Alexa Fluor 488 (AF488)-labeled monoclonal antibodies specifically targeting Bcl-2 or Bax and with nucleic acid dye. A series of fluorescent nanospheres with fluorescence intensity calibrated in the unit of molecules of equivalent soluble fluorochrome (MESF)-AF488 were used to construct a calibration curve for converting the immunofluorescence of a single mitochondrion to the number of antibodies bound to it and then to the number of proteins per mitochondrion. Under the normal condition, the measured mean copy numbers were 1300 and 220 per mitochondrion for Bcl-2 and Bax, respectively. A significant variation in protein copy number was identified, which ranged from 130 to 6000 (2.5-97.5%) for Bcl-2 and from 65 to 700 (2.5-97.5%) for Bax, respectively. We observed an approximately 4.4 fold increase of Bax copy number per mitochondrion upon 9h of apoptosis stimulation while the abundance of Bcl-2 remained almost unchanged. To the best of our knowledge, this is the first report of Bcl-2 family protein copy number and variance in single mitochondria. Collectively, we demonstrate that the HSFCM-based immunoassay provides a rapid and sensitive method for determining protein copy number distribution in single mitochondria. PMID:26176207

  7. Clinicopathological significance of Bcl-2 and Bax protein expression in human pancreatic cancer

    Institute of Scientific and Technical Information of China (English)

    Ming Dong; Jian-Ping Zhou; Hao Zhang; Ke-Jian Guo; Yu-Lin Tian; Yu-Ting Dong

    2005-01-01

    AIM: To assess the clinicopathological significance of the expression of the apoptosis-inhibitory Bcl-2 protein (pBcl-2) and the apoptosis-promoting Bax protein (pBax) in human invasive ductal carcinomas (IDCs) of the pancreas. METHODS: Fifty-nine surgical specimens of IDCs of the pancreas were stained immunohistochemically to detectpBcl-2 and pBax expressions whose correlation to tumor classification, staging, and prognosis was analyzed by univariate and multivariate analyses. RESULTS: The expression of pBcl-2 and pBax was detected in 21 of 59 (35.6%) and in 29 of 59 (49.2%) patients with IDCs of the pancreas, respectively. Neither pBcl-2 nor pBax alone was correlated to TNM staging and differentiation degree of IDCs of the pancreas according to univariate analysis. By Mantel-Cox test, the median survival time after surgery for pBcl-2(+) and pBcl-2(-) groups were 14.3 and 7.3 mo, respectively (χ2= 9.357, P = 0.002) and that for pBax(+) and pBax(-) groups were 12.9 and 10.2 mo, respectively (χ2= 0.285, P>0.05).Contingency coefficient between pBd-2 and pBax expression was 0.298, indicating that there was correlation between them (χ2= 5.74, P<0.05). The median survival time after surgery for pBd-2(+)pBax(+) and pBcl-2(+)pBax(-) groups were 14.3 and 14.1 mo, respectively, and that for pBcl-2 (-)pBax(+) and pBcl-2(-)pBax(-) groups were 5.9 and 9.9 mo, respectively. There was a significant difference between pBcl-2(+)pBax(+) and pBcl-2(-)pBax(+) (χ2 = 5.06,P<0.05), such was the case for pBcl-2(+)pBax(+) andpBcl-2(-)pBax(-) (χ2= 7.18, P<0.01). Cox proportional hazards model for multivariate analysis was applied, indicating that pBcl-2, TNM staging, age and pBax were high risk factors of post-surgical survival time. CONCLUSION: Both pBcl-2 and pBax have high expression in IDCs of the pancreas, indicating that co-expression of pBcl-2 and pBax is a good indicator of favorable prognosis in IDCs of the pancreas.

  8. TR4 orphan nuclear receptor functions as an apoptosis modulator via regulation of Bcl-2 gene expression

    International Nuclear Information System (INIS)

    While Bcl-2 plays an important role in cell apoptosis, its relationship to the orphan nuclear receptors remains unclear. Here we report that mouse embryonic fibroblast (MEF) cells prepared from TR4-deficient (TR4-/-) mice are more susceptible to UV-irradiation mediated apoptosis compared to TR4-Wildtype (TR4 +/+) littermates. Substantial increasing TR4-/- MEF apoptosis to UV-irradiation was correlated to the down-regulation of Bcl-2 RNA and protein expression and collaterally increased caspase-3 activity. Furthermore, this TR4-induced Bcl-2 gene expression can be suppressed by co-transfection with TR4 coregulators, such as androgen receptor (AR) and receptor-interacting protein 140 (RIP140) in a dose-dependent manner. Together, our results demonstrate that TR4 might function as an apoptosis modulator through induction of Bcl-2 gene expression

  9. Expression of P16 protein and Bcl-2 protein in malignant eyelid tumors

    Institute of Scientific and Technical Information of China (English)

    牛膺筠; 周占宇; 刘夫玲; 王红云

    2002-01-01

    Objective To investigate the relationship between P16 gene (the tumor suppressor gene) and the bcl-2 gene (the apoptosis inhibitor gene) and the incidence and development of malignant eyelid tumors. Methods The streptavidin-biotin-peroxidase complex immunohistochemistry method was used to study the expression of P16 gene and the bcl-2 gene in 96 cases of malignant eyelid tumors. Results Among the 96 cases, there were 40 basal cell carcinomas (BCCs), 33 squamous carcinomas and 23 sebaceous carcinoma, with P16 protein positive (nuclear staining) rates 70%, 54.6% and 56.5%, respectively. The P16 positive rate was negatively correlated with the degree of tumor histological differentiation, and the rate difference between the high differentiated carcinomas was significant (P<0.05). Positive Bcl-2 protein expression was detected in the cytoplasm. All 40 BCC cases were Bcl-2 positive, and nearly all of the tumor cells showed positive cytoplasmic expression, while in the 33 squamous cell carcinoma cases only one showed positive focal reaction, and the staining in the other 32 cases was relatively faint. None of the 23 sebaceous carcinomas expressed Bcl-2. Conclusions The expression of the P16 protein was related to the occurrence and degree of differentiation of malignant eyelid tumors. The overexpression of the Bcl-2 protein suggests that suppression of apoptosis might play a role in the tumorigenesis of BCC.

  10. Mitochondrial genome depletion in human liver cells abolishes bile acid-induced apoptosis: role of the Akt/mTOR survival pathway and Bcl-2 family proteins.

    Science.gov (United States)

    Marin, Jose J G; Hernandez, Alicia; Revuelta, Isabel E; Gonzalez-Sanchez, Ester; Gonzalez-Buitrago, Jose M; Perez, Maria J

    2013-08-01

    Acute accumulation of bile acids in hepatocytes may cause cell death. However, during long-term exposure due to prolonged cholestasis, hepatocytes may develop a certain degree of chemoresistance to these compounds. Because mitochondrial adaptation to persistent oxidative stress may be involved in this process, here we have investigated the effects of complete mitochondrial genome depletion on the response to bile acid-induced hepatocellular injury. A subline (Rho) of human hepatoma SK-Hep-1 cells totally depleted of mitochondrial DNA (mtDNA) was obtained, and bile acid-induced concentration-dependent activation of apoptosis/necrosis and survival signaling pathways was studied. In the absence of changes in intracellular ATP content, Rho cells were highly resistant to bile acid-induced apoptosis and partially resistant to bile acid-induced necrosis. In Rho cells, both basal and bile acid-induced generation of reactive oxygen species (ROS), such as hydrogen peroxide and superoxide anion, was decreased. Bile acid-induced proapoptotic signals were also decreased, as evidenced by a reduction in the expression ratios Bax-α/Bcl-2, Bcl-xS/Bcl-2, and Bcl-xS/Bcl-xL. This was mainly due to a downregulation of Bax-α and Bcl-xS. Moreover, in these cells the Akt/mTOR pathway was constitutively activated in a ROS-independent manner and remained similarly activated in the presence of bile acid treatment. In contrast, ERK1/2 activation was constitutively reduced and was not activated by incubation with bile acids. In conclusion, these results suggest that impaired mitochondrial function associated with mtDNA alterations, which may occur in liver cells during prolonged cholestasis, may activate mechanisms of cell survival accounting for an enhanced resistance of hepatocytes to bile acid-induced apoptosis. PMID:23597504

  11. MDA-7/IL-24 induces Bcl-2 denitrosylation and ubiquitin-degradation involved in cancer cell apoptosis.

    Directory of Open Access Journals (Sweden)

    Hui Tian

    Full Text Available MDA-7/IL-24 was involved in the specific cancer apoptosis through suppression of Bcl-2 expression, which is a key apoptosis regulatory protein of the mitochondrial death pathway. However, the underlying mechanisms of this regulation are unclear. We report here that tumor-selective replicating adenovirus ZD55-IL-24 leads to Bcl-2 S-denitrosylation and concomitant ubiquitination, which take part in the 26S proteasome degradation. IL-24-siRNA completely blocks Bcl-2 ubiquitination via reversion of Bcl-2 S-denitrosylation and protects it from proteasomal degradation which confirmed the significant role of MDA-7/IL-24 in regulating posttranslational modification of Bcl-2 in cancer cells. Nitric oxide (NO is a key regulator of protein S-nitrosylation and denitrosylation. The NO donor, sodium nitroprusside (SNP, down-regulates Bcl-2 S-denitrosylation, attenuates Bcl-2 ubiquitination and subsequently counteracts MDA-7/IL-24 induced cancer cell apoptosis, whereas NO inhibitor 2-(4-carboxyphenyl-4,4,5,5-tetramethylimidazoline-1-oxy-3-oxide (PTIO shows the opposite effect. At the same time, these NO modulators fail to affect Bcl-2 phosphorylation, suggesting that NO regulates Bcl-2 stability in a phosphorylation-independent manner. In addition, Bcl-2 S-nitrosylation reduction induced by ZD55-IL-24 was attributed to both iNOS decrease and TrxR1 increase. iNOS-siRNA facilitates Bcl-2 S-denitrosylation and ubiquitin-degradation, whereas the TrxR1 inhibitor auranofin prevents Bcl-2 from denitrosylation and ubiquitination, thus restrains the caspase signal pathway activation and subsequent cancer cell apoptosis. Taken together, our studies reveal that MDA-7/IL-24 induces Bcl-2 S-denitrosylation via regulation of iNOS and TrxR1. Moreover, denitrosylation of Bcl-2 results in its ubiquitination and subsequent caspase protease family activation, as a consequence, apoptosis susceptibility. These findings provide a novel insight into MDA-7/IL-24 induced growth

  12. Retinoids cause apoptosis in pancreatic cancer cells via activation of RAR-γ and altered expression of Bcl-2/Bax

    OpenAIRE

    Pettersson, F; Dalgleish, A G; Bissonnette, R P; Colston, K W

    2002-01-01

    All-trans-retinoic acid and 9-cis-retinoic acid have been reported to have inhibitory effects on pancreatic adenocarcinoma cells and we have shown that this is partly due to induction of apoptosis. In this study, the mechanisms whereby 9-cis-retinoic acid induces apoptosis in these cells were investigated. An involvement of the Bcl-2 family of proteins was shown, such that 9-cis-retinoic acid causes a decrease in the Bcl-2/Bax ratio. Overexpression of Bcl-2 also resulted in inhibition of apop...

  13. Study the Relativity of Bcl-2 Protein Expression in Apoptosis of Intervertebral Disc Cells. in Different Ages of Human Body%Bcl-2蛋白表达与人类不同年龄段椎间盘组织细胞凋亡的相关性研究

    Institute of Scientific and Technical Information of China (English)

    刘晓冬; 刘际红; 王传生; 邢淑芳; 秦博文; 王志彬

    2011-01-01

    目的:探讨凋亡相关蛋白Bcl-2在人类不同年龄段椎间盘组织细胞凋亡的作用.方法:采用脱氧核糖核苷酸末端转移酶介导的缺口末端标记法(terminal deoxynucleotidyl transferase mediated dUTP nick end labeling,TUNEL)、免疫组织化学方法以及HE染色法对人类不同年龄段正常人腰椎间盘髓核细胞对比.结果:①HE染色:在胚胎和儿童时期髓核内以脊索细胞为主,到成年后以软骨样细胞为主.从胚胎后期开始,椎间盘髓核细胞数量随年龄增长而逐渐减少,到老年阶段髓核细胞的数量已经很少(P<0.05).②TUNEL检测:胚胎后期即可见髓核细胞TUNEL反应阳性,而且在各年龄段均可见TUNEL反应阳性细胞,阳性颗粒的平均光密度值逐年增高(P<0.05).从胚胎后期到成年,TUNEL阳性细胞率随年龄增长而逐渐降低,并降到整个生命过程中的最低点;继之,TUNEL阳性细胞率又逐年升高(P<0.05).③Bcl-2蛋白免疫组织化学染色:自胚胎后期开始,Bcl-2蛋白就开始有较高水平的表达,但呈现逐年下降的趋势(P<0.05).Bcl-2蛋白阳性细胞表达率亦呈同样趋势(P<0.05).结论:在整个生命过程中,随年龄增长大量腰椎间盘髓核细胞发生凋亡,细胞数量明显减少.细胞凋亡是椎间盘细胞减少的原因之一.Bcl-2蛋白可能参与了椎间盘细胞凋亡的调节,但表达水平较低,不能阻止细胞凋亡的发生.%Objective: To explore the expression of Bcl-2 protein in apoptosis of intervertebral disc cells and gene regulation in different ages of human body. Method: The apoptotie status and the expression of Bcl-2 protein in the intervertebral disc ceils in different ages of human body were detected with TdT-mediated dUTP-biotin nick end labeling (TUNEL) and immunohistochemistry methods. Result: ①Hematoxylin and eosin staining: In embryonal and infantile stages, notochordal cells are the mainly kind of cells in different ages of human intervertebral disc

  14. Effect of U-74389G on apoptosis and bcl-2 expression following traumatic brain injury in rats

    Institute of Scientific and Technical Information of China (English)

    骆纯; 卢亦成; 朱诚; 江基尧

    2003-01-01

    Objective: To investigate the relationship between oxidative stress and apoptosis and bcl-2 expression following traumatic brain injury (TBI). Methods: Male Sprague-Dawley rats were subjected to lateral fluid percussion brain injury (FPBI) of moderate severity. U-74389G (20 mg/kg) were administered intravenously before FPBI. The neurological functions were measured by beam-walk task (BWT) and beam-balance task (BBT). In addition to morphological evidence of apoptosis, TUNEL histochemistry was used to identify DNA fragmentation in situ with both light and electron microscopic levels. The internucleosomal fragments of DNA in apoptotic cells were examined using agarose gel electrophoresis. Bcl-2 protein expression was detected by immunohistochemistry. Results: The scores of BWT and BBT were significantly improved (P<0.01) in the treated animals. The treatment significantly reduced the number of apoptotic cells that was counted in the areas of the injured hemisphere at various time points following TBI. No DNA ladder was detected in the treated rats. Bcl-2 expression was observed in the cerebral cortex, subcortical white matter, dentate gyrus, hippocampal CA1 and CA3 region ipsilateral to injured hemisphere. Bcl-2 positive cells displayed normal nuclear morphology; Little Bcl-2 positive cells revealed morphological feature of apoptosis or necrosis. The immunoreactivity of Bcl-2 protein decreased significantly in the hippocampus ipsilateral impact site as early as 6 h post-injury. During 1-3 d after injury, the bcl-2 protein expression decreased relatively slow. In the U-74389G treated groups, the downregulation of bcl-2 expression was halted. Conclusion: In this model, apoptosis is associated with an activation of lipid peroxidation. U-74389G may block oxidative stress and halt the downregulation of bcl-2 expression. These may be one of the molecular mechanisms of the neuro-protective effects by U-74389G.

  15. Downregulation of Bcl-2 Expression by miR-34a Mediates Palmitate-Induced Min6 Cells Apoptosis

    Science.gov (United States)

    Lin, Xiaojie; Huang, Zhimin; Liu, Juan; Li, Hai; Wei, Guohong; Cao, Xiaopei; Li, Yanbing

    2014-01-01

    Recent studies have demonstrated that the expression of miR-34a is significantly upregulated and associated with cell apoptosis in pancreatic β-cell treated with palmitate. Nevertheless, the underlying detailed mechanism is largely unknown. Here, we showed that miR-34a was significantly induced in Min6 pancreatic β-cell upon palmitate treatment. Elevated miR-34a promoted Min6 cell apoptosis. Intriguingly, ectopic expression of miR-34a lowered the expression of Bcl-2, an antiapoptotic protein. Luciferase reporter assay indicated the direct interaction of miR-34a with the Bcl-2 3′-UTR. Moreover, downregulated expression of Bcl-2 induced by palmitate could be restored by inhibition of miR-34a. We conclude that direct suppression of Bcl-2 by miR-34a accounts for palmitate-induced increased apoptosis rate in pancreatic β-cell. PMID:24829923

  16. Tissue factor/FVIIa activates Bcl-2 and prevents doxorubicin-induced apoptosis in neuroblastoma cells

    International Nuclear Information System (INIS)

    Tissue factor (TF) is a transmembrane protein that acts as a receptor for activated coagulation factor VII (FVIIa), initiating the coagulation cascade. Recent studies demonstrate that expression of tumor-derived TF also mediates intracellular signaling relevant to tumor growth and apoptosis. Our present study investigates the possible mechanism by which the interaction between TF and FVIIa regulates chemotherapy resistance in neuroblastoma cell lines. Gene and siRNA transfection was used to enforce TF expression in a TF-negative neuroblastoma cell line and to silence endogenous TF expression in a TF-overexpressing neuroblastoma line, respectively. The expression of TF, Bcl-2, STAT5, and Akt as well as the phosphorylation of STAT5 and Akt in gene transfected cells or cells treated with JAK inhibitor and LY294002 were determined by Western blot assay. Tumor cell growth was determined by a clonogenic assay. Cytotoxic and apoptotic effect of doxorubicin on neuroblastoma cell lines was analyzed by WST assay and annexin-V staining (by flow cytometry) respectively. Enforced expression of TF in a TF-negative neuroblastoma cell line in the presence of FVIIa induced upregulation of Bcl-2, leading to resistance to doxorubicin. Conversely, inhibition of endogenous TF expression in a TF-overexpressing neuroblastoma cell line using siRNA resulted in down-regulation of Bcl-2 and sensitization to doxorubicin-induced apoptosis. Additionally, neuroblastoma cells expressing high levels of either endogenous or transfected TF treated with FVIIa readily phosphorylated STAT5 and Akt. Using selective pharmacologic inhibitors, we demonstrated that JAK inhibitor I, but not the PI3K inhibitor LY294002, blocked the TF/FVIIa-induced upregulation of Bcl-2. This study shows that in neuroblastoma cell lines overexpressed TF ligated with FVIIa produced upregulation of Bcl-2 expression through the JAK/STAT5 signaling pathway, resulting in resistance to apoptosis. We surmise that this TF

  17. SS-A/Ro52 promotes apoptosis by regulating Bcl-2 production

    International Nuclear Information System (INIS)

    Highlights: ► Ro52low HeLa cells are resistant to apoptosis upon various stimulations. ► Ro52 is upregulated by IFN-α, etoposide, or IFN-γ and anti-Fas Ab. ► Ro52-mediated apoptosis is independent of p53. ► Ro52 selectively regulates Bcl-2 expression. -- Abstract: SS-A/Ro52 (Ro52), an autoantigen in systemic autoimmune diseases such as systemic lupus erythematosus and Sjögren’s syndrome, has E3 ligase activity to ubiquitinate proteins that protect against viral infection. To investigate Ro52’s role during stress, we transiently knocked it down in HeLa cells by siRo52 transfection. We found that Ro52low HeLa cells were significantly more resistant to apoptosis than wild-type HeLa cells when stimulated by H2O2- or diamide-induced oxidative stress, IFN-α, IFN-γ and anti-Fas antibody, etoposide, or γ-irradiation. Furthermore, Ro52-mediated apoptosis was not influenced by p53 protein level in HeLa cells. Depleting Ro52 in HeLa cells caused Bcl-2, but not other Bcl-2 family molecules, to be upregulated. Taken together, our data showed that Ro52 is a universal proapoptotic molecule, and that its proapoptotic effect does not depend on p53, but is exerted through negative regulation of the anti-apoptotic protein Bcl-2. These findings shed light on a new physiological role for Ro52 that is important to intracellular immunity.

  18. SS-A/Ro52 promotes apoptosis by regulating Bcl-2 production

    Energy Technology Data Exchange (ETDEWEB)

    Jauharoh, Siti Nur Aisyah [Department of Clinical Pathology and Immunology, Kobe University Graduate School of Medicine, Hyogo 650-0017 (Japan); Faculty of Medicine and Health Science, Syarif Hidayatullah State Islamic University, Jakarta 15412 (Indonesia); Saegusa, Jun; Sugimoto, Takeshi [Department of Clinical Pathology and Immunology, Kobe University Graduate School of Medicine, Hyogo 650-0017 (Japan); Ardianto, Bambang [Department of Clinical Pathology and Immunology, Kobe University Graduate School of Medicine, Hyogo 650-0017 (Japan); Department of Child Health, Faculty of Medicine, Gadjah Mada University, Yogyakarta 55282 (Indonesia); Kasagi, Shimpei; Sugiyama, Daisuke; Kurimoto, Chiyo [Department of Clinical Pathology and Immunology, Kobe University Graduate School of Medicine, Hyogo 650-0017 (Japan); Tokuno, Osamu; Nakamachi, Yuji [Department of Laboratory Medicine, Kobe University Hospital, Hyogo 650-0017 (Japan); Kumagai, Shunichi [Department of Clinical Pathology and Immunology, Kobe University Graduate School of Medicine, Hyogo 650-0017 (Japan); Kawano, Seiji, E-mail: sjkawano@med.kobe-u.ac.jp [Department of Clinical Pathology and Immunology, Kobe University Graduate School of Medicine, Hyogo 650-0017 (Japan); Department of Laboratory Medicine, Kobe University Hospital, Hyogo 650-0017 (Japan)

    2012-01-06

    Highlights: Black-Right-Pointing-Pointer Ro52{sup low} HeLa cells are resistant to apoptosis upon various stimulations. Black-Right-Pointing-Pointer Ro52 is upregulated by IFN-{alpha}, etoposide, or IFN-{gamma} and anti-Fas Ab. Black-Right-Pointing-Pointer Ro52-mediated apoptosis is independent of p53. Black-Right-Pointing-Pointer Ro52 selectively regulates Bcl-2 expression. -- Abstract: SS-A/Ro52 (Ro52), an autoantigen in systemic autoimmune diseases such as systemic lupus erythematosus and Sjoegren's syndrome, has E3 ligase activity to ubiquitinate proteins that protect against viral infection. To investigate Ro52's role during stress, we transiently knocked it down in HeLa cells by siRo52 transfection. We found that Ro52{sup low} HeLa cells were significantly more resistant to apoptosis than wild-type HeLa cells when stimulated by H{sub 2}O{sub 2}- or diamide-induced oxidative stress, IFN-{alpha}, IFN-{gamma} and anti-Fas antibody, etoposide, or {gamma}-irradiation. Furthermore, Ro52-mediated apoptosis was not influenced by p53 protein level in HeLa cells. Depleting Ro52 in HeLa cells caused Bcl-2, but not other Bcl-2 family molecules, to be upregulated. Taken together, our data showed that Ro52 is a universal proapoptotic molecule, and that its proapoptotic effect does not depend on p53, but is exerted through negative regulation of the anti-apoptotic protein Bcl-2. These findings shed light on a new physiological role for Ro52 that is important to intracellular immunity.

  19. Fish oil administration mediates apoptosis of Walker 256 tumor cells by modulation of p53, Bcl-2, caspase-7 and caspase-3 protein expression

    OpenAIRE

    Borghetti, Gina; Yamaguchi, Adriana Aya; Aikawa, Julia; Yamazaki, Ricardo Key; de Brito, Gleisson Alisson Pereira; Fernandes, Luiz Claudio

    2015-01-01

    Background Several studies have been shown pro-apoptotic effects of fish oil (FO), rich in n-3 polyunsaturated fatty acids (n-3 PUFA) on cancer cells. Nevertheless, few in vivo experiments have provided data of its ability on apoptosis protein expression in tumor tissue. Thus, in this study we investigate the effect of FO supplementation on apoptosis protein expression in Walker 256 tumor bearing rats. Male Wistar rats were randomly assigned to three groups: fed with regular chow (W); fed reg...

  20. Upregulation of Bax and Bcl-2 following prenatal cocaine exposure induces apoptosis in fetal rat brain

    Directory of Open Access Journals (Sweden)

    DaLiao Xiao, Lubo Zhang

    2008-01-01

    Full Text Available Cocaine abuse during pregnancy has been associated with numerous adverse perinatal outcomes. Aims: The present study was to determine whether prenatal cocaine exposure induced apoptosis and the possible role of Bcl-2 family genes in the programming cell death in fetal rat brain. Main methods: Pregnant rats were treated with cocaine subcutaneously (30 & 60 mg/kg/day from day 15 to 21 of gestation. Then the fetal and maternal brains were isolated. Key findings: Cocaine produced a dose-dependent decrease in fetal brain weight and brain/body weight ratio (P<0.05. Apoptotic nuclei in fetal brain were increased from 2.6 ± 0.1 (control to 8.1± 0.6 (low dose and 10.4 ± 0.2% (high dose (P<0.05. In accordance, cocaine dose dependently increased activities of caspase-3, caspase-8, and caspase-9 (% of control in the fetal brain by 177%, 155%, 174%, respectively, at 30 mg/kg/day, and by 191%, 176%, 274%, respectively, at 60 mg/kg/day. In contrast, cocaine showed no effect on caspase activities in the maternal brain. Cocaine produced a dose-dependent increase in both Bcl-2 and Bax protein expression in the fetal brain, and increased the ratio of Bax/Bcl-2 at dose of 30 mg/kg/day (P<0.05. Significance: Our study has demonstrated that prenatal cocaine exposure induces apoptosis in the fetal brain, and suggested that up-regulating Bax/Bcl-2 gene expression may be involved in cocaine-induced apoptosis. The increased apoptosis of neuronal cells in the fetal brain is likely to play a key role in cocaine-induced neuronal defects during fetal development.

  1. Combined expression of gastrointestinal hormone SP and anti-apoptosis geneBcl-2 in gastric carcinoma

    Institute of Scientific and Technical Information of China (English)

    Yan Ling Feng; Qin Xian Zhang; Sheng Lei Li

    2000-01-01

    AIM To study the combined expression of gastrointestinal hormone substance P and anti-apoptosis gene Bcl-2 in gastric carcinoma and its significance.METHODS Substance P and Bcl-2 protein expression was examined by the S-P immunohistochemicalmethod in 33 cases of gastric carcinoma, 17 adjacent the carcinoma and 13 normal gastric mucoma.RESULTS Positive expression of SP in gastric carcinoma was higher than that of both adjacent and normalmucosa (P 0.05). The expression of bcl-2 both in gastric carcinoma and adjacent tissues werehigher than that of normal gastric mucosa (P< 0.05-0.01). But the positive expression of Bcl-2 had nostatistical significance between gastric carcinoma and adjacent tissues.CONCLUSION Both gastrointestinal hormone SP and Bcl-2 gene have synergistic expression in gastriccarcinoma, indicating that they all take part in the occurrence of gastric carcinoma. Abnormal expression ofBcl-2 gene occurred in benign gastric pathological changes, once they become carcinoma, the positiveexpression of cell is no more increased, possibly because that there is no more increase of the intensity of Bcl-2 inhibition of cell apoptosis.

  2. The role of the expression of bcl-2, p53 gene in tamoxifen-induced apoptosis of breast cancer cells and its relationship with hormone receptor status

    Energy Technology Data Exchange (ETDEWEB)

    Noh, Woo Chul; Ham, Yong Ho [Korea Cancer Center Hospital, Seoul (Korea, Republic of)

    1998-01-01

    To investigate the relationship of bcl-2, p53, ER and tamoxifen-induced apoptosis of breast cancer cells, MCF-7 (ER+/bcl-2+/p53-) and MB MDA 468 (ER-/bcl-2-/p53+) cell line were cultured in estrogen-free condition. E2(10`-`9M) and tamoxifen (10`-`5M) were added to the media. The changes of bcl-2 and mutant p53 protein were checked by Western blot and apoptosis were measured by flowcytometry. In MCF-7 cells, we found that treatment with tamoxifen resulted in a decrease in bcl-2 protein level, but produced no change in mutant p53. In MB MDA 468 cell however, there were no changes of bcl-2 and mutant p53 protein level when E2 or tamoxifen were added. Apoptotic cells increased with time-dependent pattern when tamoxifen was added to MCF-7 cells. According to these result, ER+/blc-2+/mutant p53- cells, when treated with tamoxifen, were converted into bcl-2/mutant p53- cells which were more prone to apoptosis than bcl-2-/mutant p53+ cells. The paradoxical correlation of bcl-2 and ER which had been observed in clinical studies might be explained with this results and bcl-2 protein seems to be one of important factors that can predict the effect of hormone therapy. (author). 26 refs., 5 figs

  3. Deregulation of apoptosis mediators' p53 and bcl2 in lung tissue of COPD patients

    Directory of Open Access Journals (Sweden)

    Pentilas Nikolaos

    2010-04-01

    Full Text Available Abstract Abnormal apoptotic events in chronic obstructive pulmonary disease (COPD subvert cellular homeostasis and may play a primary role in its pathogenesis. However, studies in human subjects are limited. p53 and bcl2 protein expression was measured by western blot on lung tissue specimens from 43 subjects (23 COPD smokers and 20 non-COPD smokers, using beta-actin as internal control. Additionally, p53 and bcl2 expression patterns were evaluated by immunohistochemistry in formalin-fixed, paraffin-embedded lung tissue sections from the same individuals. Western blot analysis showed statistically significant increased p53 protein levels in COPD smokers in comparison with non-COPD smokers (p = 0.038, while bcl2 protein levels were not statistically different between the two groups. Lung immunohistochemistry showed increased ratio of positive p53-stained type II pneumocytes/total type II pneumocytes in COPD smokers compared to non-COPD smokers (p = 0.01, whereas the p53 staining ratio in alveolar macrophages and in lymphocyte-like cells did not differ statistically between the two groups. On the other hand, bcl2 expression did not differ between the two groups in all three cell types. The increased expression of pro-apoptotic p53 in type II pneumocytes of COPD patients not counterbalanced by the anti-apoptotic bcl2 could reflect increased apoptosis in the alveolar epithelium of COPD patients. Our results confirm previous experiments and support the hypothesis of a disturbance in the balance between the pro- and anti-apoptotic mediators in COPD.

  4. Effects of Exercise Pre-Conditioning on Hippocampus Expression of Bcl-2 and Bax Protein and Apoptosis Following Ischemia/Reperfusion Injury in Male Rats

    OpenAIRE

    Nabi Shamsaei; Hamid Rajabi; Nahid Aboutaleb; Farnaz Nikbakht; Pezhman Motamedi; Mehdi Khaksari; Sohaila Erfani

    2015-01-01

    Introduction: Cerebral ischemia/reperfusion leads to loss of vulnerable neurons by apoptosis in specific brain regions specially in the hippocampus. There is some evidence indicating that the neuroprotective effects of physical activity on the brain. Therefore,the main purpose of this study was to investigate the effect of exercise pre-conditioning on apoptosis-related proteins expression in hippocampal CA1 neurons after induction of ischemia. Methods: 21 Male rats weighing 260-300g were ...

  5. Affinity purification-mass spectrometry analysis of bcl-2 interactome identified SLIRP as a novel interacting protein.

    Science.gov (United States)

    Trisciuoglio, D; Desideri, M; Farini, V; De Luca, T; Di Martile, M; Tupone, M G; Urbani, A; D'Aguanno, S; Del Bufalo, D

    2016-01-01

    Members of the bcl-2 protein family share regions of sequence similarity, the bcl-2 homology (BH) domains. Bcl-2, the most studied member of this family, has four BH domains, BH1-4, and has a critical role in resistance to antineoplastic drugs by regulating the mitochondrial apoptotic pathway. Moreover, it is also involved in other relevant cellular processes such as tumor progression, angiogenesis and autophagy. Deciphering the network of bcl-2-interacting factors should provide a critical advance in understanding the different functions of bcl-2. Here, we characterized bcl-2 interactome by mass spectrometry in human lung adenocarcinoma cells. In silico functional analysis associated most part of the identified proteins to mitochondrial functions. Among them we identified SRA stem-loop interacting RNA-binding protein, SLIRP, a mitochondrial protein with a relevant role in regulating mitochondrial messenger RNA (mRNA) homeostasis. We validated bcl-2/SLIRP interaction by immunoprecipitation and immunofluorescence experiments in cancer cell lines from different histotypes. We showed that, although SLIRP is not involved in mediating bcl-2 ability to protect from apoptosis and oxidative damage, bcl-2 binds and stabilizes SLIRP protein and regulates mitochondrial mRNA levels. Moreover, we demonstrated that the BH4 domain of bcl-2 has a role in maintaining this binding. PMID:26866271

  6. A component of green tea (-)-epigallocatechin-3-gallate, promotes apoptosis in T24 human bladder cancer cells via modulation of the PI3K/Akt pathway and Bcl-2 family proteins

    International Nuclear Information System (INIS)

    Bladder cancer is the fourth most common cancer in men and ninth most common in women. It has a protracted course of progression and is thus an ideal candidate for chemoprevention strategies and trials. This study was conducted to evaluate the chemopreventive/antiproliferative potential of (-)-epigallocatechin gallate (EGCG, the major phytochemical in green tea) against bladder cancer and its mechanism of action. Using the T24 human bladder cancer cell line, we found that EGCG treatment caused dose- and time-dependent inhibition of cellular proliferation and cell viability, and induced apoptosis. Mechanistically, EGCG inhibits phosphatidylinositol 3'-kinase/Akt activation that, in turn, results in modulation of Bcl-2 family proteins, leading to enhanced apoptosis of T24 cells. These findings suggest that EGCG may be an important chemoprevention agent for the management of bladder cancer

  7. Effect of Bcl-2/Bax gene expression on apoptosis of spermatogenic cells of mouse testes induced by low dose radiation

    International Nuclear Information System (INIS)

    The different kinds of spermatogenic cells were separated using density gradient centrifugation and their apoptosis and Bcl-2 and Bax protein expression were measured with flow cytometry and immunohistochemical method, respectively. The results showed the apoptosis in all kinds of spermatogenic cells induced by low dose radiation (LDR) had a obvious regularity. When the doses were 0.025 and 0.05 Gy, spermatogonia apoptosis was dominant. With the increase of irradiation dose (0.075-0.2 Gy), spermatocytes also showed an apoptotic change, but the apoptotic percentage of spermatogonia was significantly higher than that of spermatocytes. Moreover, the apoptosis of spermatids and spermatozoa scarcely occurred after LDR. Bax protein was primarily expressed in spermatogonia and spermatocytes, and the former was significantly higher than that of the latter after LDR. With the increase of irradiation dose, Bax protein expression showed a upgrading tendency, but that of spermatids and spermatozoa scarcely occurred. Bcl-2 protein was primarily expressed in spermatids and spermatozoa, but the Bcl-2 protein expressions of spermatogonia and spermatocytes scarcely occurred after LDR. These results imply that the interacting regulation of Bcl-2 and Bax gene expression might be involved in selective apoptosis of spermatogenic cells induced by LDR, which provided an experimental evidence for further exploring the apoptotic mechanism of adaptive response of spermatogenic cells by LDR

  8. Bid, a widely expressed proapoptotic protein of the Bcl-2 family, displays lipid transfer activity

    DEFF Research Database (Denmark)

    Esposti, M D; Erler, Janine Terra; Hickman, J A;

    2001-01-01

    Bid is an abundant proapoptotic protein of the Bcl-2 family that is crucial for the induction of death receptor-mediated apoptosis in primary tissues such as liver. Bid action has been proposed to involve the relocation of its truncated form, tBid, to mitochondria to facilitate the release of apo...

  9. Detection of Protein BCL2/JH Rearrangement in Epidermoid Carcinomas of Mouth and Pharynx

    Directory of Open Access Journals (Sweden)

    Montovani, Jair

    2010-09-01

    Full Text Available Introduction: The BCL2 protein found in the internal mothocondrial membrana regulates the apoptosis preventing the programmed cell death. The translocation (14:18, detected in 70 to 85% of the follicular lymphoma, lead the super expression of BCL2 protein, by juxtaposition of BCL2 gene to the JH segment of the immunoglobulins' heavy chain gene. However, the found of the BCL2 expression in head and neck carcinoma are contradictious. Objective: To investigate the presence of the translocation (14:18 of the BCL2 gene in head and neck carcinoma. Method: Sixteen DNA samplers were examinated being 13 of squamous cells carcinoma (SCC and 3 of epidermoid (CE, y means of chain reaction of the polymerase (PCR. Results: The BCL2/JH rearrangement in 2 (15% of the CCE 13 cases and in none of the 3 cases of CE. The average of the frequency of molecules with rearrangement was 46,44x107. Was not observed association between the rearrangement presence and the exhibition to tobacco and alcohol (p=0, 6545. Conclusion: Different from the results found in follicular lymphoma, the presence of the translocation (14; 18 in head and neck carcinomas is not common and, when it occurs, it can be an occasional mutation not associated to exhibition to the tobacco and alcohol.

  10. Simultaneous Detection of Tumor Cell Apoptosis Regulators Bcl-2 and Bax through a Dual-Signal-Marked Electrochemical Immunosensor.

    Science.gov (United States)

    Zhou, Shiwei; Wang, Yingying; Zhu, Jun-Jie

    2016-03-30

    B-cell lymphoma 2 (Bcl-2) and Bcl-2-associated X protein (Bax) are often used to monitor the apoptosis of tumor cells and evaluate cancer drug effect. In this work, a novel sandwich-type dual-signal-marked electrochemical biosensor was fabricated for simultaneous detection of Bcl-2 and Bax proteins. Reduced graphene oxide (RGO) layers were used as substrate to immobilize Bcl-2 and Bax antibodies for further capturing target antigens. CdSeTe@CdS quantum dots (QDs) and Ag nanoclusters (NCs) with antibody modification and mesoporous silica amplification were used as signal probes, which were proportional to the amount of Bcl-2 and Bax antigens. Mesoporous SiO2 can provide a larger surface area, more effectively charged by ethylene imine polymer or poly(diallyldimethylammonium chloride) to adsorb more probes. The Bcl-2 and Bax proteins were determined indirectly by the detection of oxidation peak currents of Cd and Ag using anodic stripping voltammetry, showing a good linear relationship in the protein concentration range from 1 ng/mL to 250 ng/mL. The detection limit of trace protein level was ∼0.5 fmol. The biosensor was further introduced to investigate Bcl-2 and Bax expressions from nilotinib-treated chronic myeloid leukemia K562 cells. With the increase of drug dosage and incubation time, the up-regulation for Bax and down-regulation for Bcl-2 were observed, which indicated that the apoptosis level of K562 cells could be regulated by Bcl-2 family. The ratio of Bax/Bcl-2 was further calculated for evaluation of its drug effect and apoptosis level. The limited cell amount for detection reached less than 1 × 10(3) cells, much lower than traditional methods. Furthermore, completely independent detection step and stable acid solutions containing Ag(+) and Cd(2+) for long-time storage contribute to reducing the error from the sample differences and avoiding the potential errors from the photodegradation of fluorescent probes, enzymolysis of DNA, or inactivation of

  11. Tissue factor/FVIIa activates Bcl-2 and prevents doxorubicin-induced apoptosis in neuroblastoma cells

    Directory of Open Access Journals (Sweden)

    Alvarado Carlos S

    2008-03-01

    Full Text Available Abstract Background Tissue factor (TF is a transmembrane protein that acts as a receptor for activated coagulation factor VII (FVIIa, initiating the coagulation cascade. Recent studies demonstrate that expression of tumor-derived TF also mediates intracellular signaling relevant to tumor growth and apoptosis. Our present study investigates the possible mechanism by which the interaction between TF and FVIIa regulates chemotherapy resistance in neuroblastoma cell lines. Methods Gene and siRNA transfection was used to enforce TF expression in a TF-negative neuroblastoma cell line and to silence endogenous TF expression in a TF-overexpressing neuroblastoma line, respectively. The expression of TF, Bcl-2, STAT5, and Akt as well as the phosphorylation of STAT5 and Akt in gene transfected cells or cells treated with JAK inhibitor and LY294002 were determined by Western blot assay. Tumor cell growth was determined by a clonogenic assay. Cytotoxic and apoptotic effect of doxorubicin on neuroblastoma cell lines was analyzed by WST assay and annexin-V staining (by flow cytometry respectively. Results Enforced expression of TF in a TF-negative neuroblastoma cell line in the presence of FVIIa induced upregulation of Bcl-2, leading to resistance to doxorubicin. Conversely, inhibition of endogenous TF expression in a TF-overexpressing neuroblastoma cell line using siRNA resulted in down-regulation of Bcl-2 and sensitization to doxorubicin-induced apoptosis. Additionally, neuroblastoma cells expressing high levels of either endogenous or transfected TF treated with FVIIa readily phosphorylated STAT5 and Akt. Using selective pharmacologic inhibitors, we demonstrated that JAK inhibitor I, but not the PI3K inhibitor LY294002, blocked the TF/FVIIa-induced upregulation of Bcl-2. Conclusion This study shows that in neuroblastoma cell lines overexpressed TF ligated with FVIIa produced upregulation of Bcl-2 expression through the JAK/STAT5 signaling pathway, resulting

  12. Effect of low dose radiation on Bcl-2 protein expressions in mouse immune system

    International Nuclear Information System (INIS)

    Objective: In the present study the authors observed the effect of dose radiation (LDR) on the Bcl-2 protein expressions in mouse immune system. Methods: Immunohistochemistry and image analysis were used. Results: These results showed that Bcl-2 protein had a basic expression in the sham-irradiated group. As the time passed, the expressions of Bcl-2 protein gradually increased following whole-body irradiation with 75 mGy X-rays. It reached the peak value at 12-24 hours, and then returned to the basic level at 72 hours. Conclusion: These findings reveal the molecular mechanisms of the J-shape dose response curve occurring in apoptosis in the immune organs and the enhancement of the immune function after LDR

  13. Di-(2-ethylhexyl) phthalate induces apoptosis of GC-2spd cells via TR4/Bcl-2 pathway.

    Science.gov (United States)

    Zhu, Lishan; Lu, Jinchang; Tang, Xiao; Fu, Guoqing; Duan, Peng; Quan, Chao; Zhang, Ling; Zhang, Zhibing; Chang, Wei; Shi, Yuqin

    2016-06-01

    Di-(2-ethylhexyl) phthalate (DEHP) is a widely used environmental endocrine disruptor. Many studies have reported that DEHP exposure causes reproductive toxicity and cells apoptosis. However, the mechanism by which DEHP exposure causes male reproductive toxicity remains unknown. This study investigated the role of the testicular orphan nuclear receptor4 (TR4)/Bcl-2 pathway in apoptosis induced by DEHP, which resulted in reproductive damage. To elucidate the mechanism underpinning the male reproductive toxicity of DEHP, we sought to investigate apoptotic effects, expression levels of TR4/Bcl-2 pathway in GC-2spd cells, including TR4, Bcl-2 and caspase-3. GC-2spd cells were exposed to various concentrations of DEHP (0, 50, 100, or 200μM). The results indicated that, with the increase of the concentrations of DEHP, the survival rate of cell decreased gradually. DEHP exposure at over 100μM significantly induced apoptotic cell death. DEHP decreased SOD and GSH-Px activity in 200μM group. Compared to the control group, the mRNA levels of caspase-3 increased significantly, however, Bcl-2 mRNA decreased (PBcl-2 and procaspase-3 protein levels. Taken together, these results lead us to speculate that in vitro exposure to DEHP might induce apoptosis in GC-2spd cells through the TR4/Bcl-2 pathway. PMID:27084994

  14. Fibroblast Growth Factor-2 and the HIV-1 Tat Protein Synergize in Promoting Bcl-2 Expression and Preventing Endothelial Cell Apoptosis: Implications for the Pathogenesis of AIDS-Associated Kaposi's Sarcoma

    Directory of Open Access Journals (Sweden)

    Cecilia Sgadari

    2011-01-01

    Here we show that the development of angioproliferative lesions promoted in mice by combined Tat and FGF-2 associates with an increase in the levels of expression of the antiapoptotic Bcl-2 protein. Upregulation of Bcl-2 expression by combined FGF-2 and Tat occurs also in vitro, and this protects human primary endothelial cells from programmed cell death. As Bcl-2 is expressed in human KS lesions in a fashion paralleling the progression of the disease, these findings suggest a molecular mechanism by which Tat and FGF-2 cooperate in KS maintenance and progression in HIV-infected individuals.

  15. Zerumbone induced apoptosis in liver cancer cells via modulation of Bax/Bcl-2 ratio

    Directory of Open Access Journals (Sweden)

    Azimahtol Hawariah LP

    2007-04-01

    Full Text Available Abstract Background Zerumbone is a cytotoxic component isolated from Zingiber zerumbet Smith, a herbal plant which is also known as lempoyang. This new anticancer bioactive compound from Z. zerumbet was investigated for its activity and mechanism in human liver cancer cell lines. Results Zerumbone significantly showed an antiproliferative activity upon HepG2 cells with an IC50 of 3.45 ± 0.026 μg/ml. Zerumbone was also found to inhibit the proliferation of non-malignant Chang Liver and MDBK cell lines. However the IC50 obtained was higher compared to the IC50 for HepG2 cells (> 10 μg/ml. The extent of DNA fragmentation was evaluated by the Tdt-mediated dUTP nick end labelling assay which showed that, zerumbone significantly increased apoptosis in HepG2 cells in a time-course manner. In detail, the apoptotic process triggered by zerumbone involved the up-regulation of pro-apoptotic Bax protein and the suppression of anti-apoptotic Bcl-2 protein expression. The changes that occurred in the levels of this antagonistic proteins Bax/Bcl-2, was independent of p53 since zerumbone did not affect the levels of p53 although this protein exists in a functional form. Western blotting analysis for Bax protein was further confirmed qualitatively with an immunoassay that showed the distribution of Bax protein in zerumbone-treated cells. Conclusion Therefore, zerumbone was found to induce the apoptotic process in HepG2 cells through the up and down regulation of Bax/Bcl-2 protein independently of functional p53 activity.

  16. CO-EXPRESSIONS OF SURVIVIN GENE,BCL-2 AND BAX PROTEINS IN OVARIAN CARCINOMA

    Institute of Scientific and Technical Information of China (English)

    林蓓; 张淑兰; 赵长清

    2004-01-01

    Objective To characterize the cellular properties of ovarian cancer, we examined the correlation between the expression of apoptosis-related gene survivin and those of Bcl-2 and Bar proteins. Methods Expressions of survivin mRNA, and Bcl-2 and Bax proteins in 35 cases of ovarian carcinoma, 10 cases of borderline carcinoma, 10 cases of benign tumors and 10 cases of normal tissue were evaluated by reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry SABC method, respectively. Results Expression of survivin gene was detected in a significantly greater proportion in ovarian carcinoma and borderline carcinoma than those in benign tumors and normal tissues. Although there was no relationship between expression of survivin gene and FIGO stage, histologic grade, pathological type and lymphatic metastasis, expressions of Bcl-2 and Bar proteins were positively and negatively correlated with that of survivin gene, respectively. Conclusion Survivin may play an important role in pathogenesis of ovarian carcinoma, with a synergistic role of apoptosis-related gene Bcl-2protein and an antagonistic role of Bax protein in formation and progression of ovarian carcinoma.

  17. Odontoblast-targeted Bcl-2 Overexpression Impairs Dentin Formation

    OpenAIRE

    Zhang, Wenjian; Ju, Jun; Gronowicz, Gloria

    2010-01-01

    Apoptosis has been described extensively in tooth development, which is under tight control of multiple apoptosis regulators, including anti-apoptotic protein Bcl-2. However, it is totally unclear how Bcl-2 is related to odontogenesis, especially dentinogenesis. Using a transgenic mouse Col2.3Bcl-2 in which human Bcl-2 was overexpressed in odontoblasts, the effect of Bcl-2 on dentinogenesis was investigated. Overexpression of Bcl-2 was detected by immunohistochemistry and Western blot. Odonto...

  18. The BCL2 rheostat in glucocorticoid-induced apoptosis of acute lymphoblastic leukemia

    Science.gov (United States)

    Ploner, C; Rainer, J; Niederegger, H; Eduardoff, M; Villunger, A; Geley, S; Kofler, R

    2016-01-01

    Glucocorticoid (GC)-induced apoptosis is essential in the treatment of acute lymphoblastic leukemia (ALL) and related malignancies. Pro- and anti-apoptotic members of the BCL2 family control many forms of apoptotic cell death, but the extent to which this survival ‘rheostat’ is involved in the beneficial effects of GC therapy is not understood. We performed systematic analyses of expression, GC regulation and function of BCL2 molecules in primary ALL lymphoblasts and a corresponding in vitro model. Affymetrix-based expression profiling revealed that the response included regulations of pro-apoptotic and, surprisingly, anti-apoptotic BCL2 family members, and varied among patients, but was dominated by induction of the BH3-only molecules BMF and BCL2L11/Bim and repression of PMAIP1/Noxa. Conditional lentiviral gene overexpression and knock-down by RNA interference in the CCRF-CEM model revealed that induction of Bim, and to a lesser extent that of BMF, was required and sufficient for apoptosis. Although anti-apoptotic BCL2 members were not regulated consistently by GC in the various systems, their overexpression delayed, whereas their knock-down accelerated, GC-induced cell death. Thus, the combined clinical and experimental data suggest that GCs induce both pro- and anti-apoptotic BCL2 family member-dependent pathways, with the outcome depending on cellular context and additional signals feeding into the BCL2 rheostat. PMID:18046449

  19. Homologous recombination control by the anti-apoptotic onco-protein Bcl-2

    International Nuclear Information System (INIS)

    This research thesis deals with the different biological mechanisms, notably the repair and apoptosis mechanisms induced by irradiation in cells. After a presentation of the genotoxic stress and DNA repair mechanisms, the author discusses the cellular response to a DNA double-strand break, and the regulation of these response mechanisms (how a cellular response emerges: life or death). The next part deals with the apoptosis (cell death by necrosis or apoptosis), and presents the BCL-2 protein family. Results are then reported on laboratory studies of the effect of this protein family

  20. Changes of expression of apoptosis-related proteins Smac and Bcl-2 in Parkinsonˊs disease rat induced by Rotenone%鱼藤酮致帕金森病大鼠黑质中Smac和Bcl-2的表达及意义

    Institute of Scientific and Technical Information of China (English)

    张延平; 李彦改; 徐晓臣; 王英杰; 李印杰

    2015-01-01

    目的:研究鱼藤酮致帕金森病( Parkinsonˊs disease,PD)大鼠脑黑质中凋亡相关蛋白Smac和Bcl-2表达的改变。方法:将Witstar大鼠随机分为对照组和实验组。对照组10只背部皮下注射葵花油1ml/kg,实验组25只分为A、B、C三组,按照3.0(5只)、2.0(10只)和1.0(10只)mg/(kg·d)背部皮下注射鱼藤酮(鱼藤酮溶解在葵花籽油中,充分震荡混匀后4℃避光保存)。结果:透射电镜观察下,鱼藤酮处置的实验组神经元细胞皱缩,胞质致密,核染色质边集,有部分细胞胞核裂解,胞质芽突脱落,形成凋亡小体。并且随着鱼藤酮染毒剂量的增大,凋亡小体形成更加明显。免疫组化染色显示,Smac的阳性表达实验组高于对照组,Bcl-2的阳性表达实验组低于对照组。结论:鱼藤酮具有明显的神经毒性,能导致大鼠脑内DA能神经元的损伤,细胞凋亡参与了鱼藤酮帕金森模型大鼠黑质多巴胺神经细胞的损伤。%Objective:To study the changes of expression of apoptosis-related proteins Smac and Bcl-2 in the midbrain substantia nigra in Parkinsonˊs disease rat induced by Rotenone. Methods:Witstar rats were randomly divid-ed into control group and experimental group. Control group 10 rats were treated by subcutaneously injection of sun-flower oil 1ml/kg,25 in experimental group were divided into A,B,C three groups,with 3. 0(5),2. 0(10)and 1. 0 (10)mg/(kg·d)(subcutaneous injection of Rotenone dissolved in sunflower oil,shake evenly mixed 4℃ stored a-way from light). Results:TEM observated results,neuronal cells in experimental group shrinkage Rotenone treatment, cytoplasmic dense,the nuclear chromatin,nuclear fragmentation and some cells,cytoplasmic buds abscission,and for-mation of apoptotic bodies. And with the increase of the dose of Rotenone,apoptotic body formation was more obvious.Immunohistochemical staining showed positive expression of Smac

  1. Born to be alive: a role for the BCL-2 family in melanoma tumor cell survival, apoptosis, and treatment

    Directory of Open Access Journals (Sweden)

    JerryEdwardChipuk

    2011-10-01

    Full Text Available The global incidence of melanoma has dramatically increased during the recent decades, yet the advancement of primary and adjuvant therapies has not kept a similar pace. The development of melanoma is often centered on cellular signaling that hyper-activates survival pathways, while inducing a concomitant blockade to cell death. Aberrations in cell death signaling not only promote tumor survival and enhanced metastatic potential, but also create resistance to anti-tumor strategies. Chemotherapeutic agents target melanoma tumor cells by inducing a form of cell death called apoptosis, which is governed by the BCL-2 family of proteins. The BCL-2 family is comprised of anti-apoptotic proteins (e.g., BCL-2, BCL-xL, and MCL-1 and pro-apoptotic proteins (e.g., BAK, BAX, and BIM, and their coordinated regulation and function are essential for optimal responses to chemotherapeutics. Here we will discuss what is currently known about the mechanisms of BCL-2 family function with a focus on the signaling pathways that maintain melanoma tumor cell survival. Importantly, we will critically evaluate the literature regarding how chemotherapeutic strategies directly impact on BCL-2 family function and offer several suggestions for future regimens to target melanoma and enhance patient survival.

  2. Study of immunohistochemical demonstration of Bcl-2 protein in ameloblastoma and keratocystic odontogenic tumor

    Directory of Open Access Journals (Sweden)

    C S Sindura

    2013-01-01

    Full Text Available Background: The Bcl-2 (B-cell lymphoma gene product also known as apoptotic inhibitor is expressed in many normal and tumor tissues. This Bcl-2 gene protects the cell by blocking postmitotic differentiation from apoptosis, thus maintaining the stem cell pool. Objective: To study the expression of Bcl-2 protein in ameloblastoma and keratocystic odontogenic tumor (KCOT to determine their apoptotic behaviors and to analyze biological nature of KCOT, which has higher proliferative potential and aggressive clinical behavior like odontogenic tumors. Materials and Methods: Formalin-fixed paraffin sections of ameloblastoma (n = 20 and KCOT (n = 20 are considered for immunohistochemical analysis using monoclonal antibody against antihuman Bcl-2 oncoprotein. Lymphomas (n = 3 were used as controls. Statistical Analysis: The statistical analysis was performed using software package of social science version 16.The data were analyzed using Chi-square test and Student′s t test. In all the above tests, P < 0.05 was accepted as statistically significant. Results: The positive ratio of Bcl-2 was 85% (17/20 in ameloblastoma, 85% (17/20 in KCOT and 100% (3/3 in lymphomas. Bcl-2 was expressed in peripheral cells and few scattered cells of stellate reticulum in ameloblastoma. KCOT showed strong positivity for Bcl-2 mainly in the basal layer. Interpretation and Conclusion: The present study demonstrates the aggressive nature of KCOT and intrinsic growth potential of its lining epithelium. This study clearly demonstrates that KCOT like ameloblastoma demonstrates aggressive clinical and noticeable invasive behavior. Therefore, it is now considered as no longer a developmental cyst but as odontogenic tumor.

  3. Combined transfection of Bcl-2 siRNA and miR-15a oligonucleotides enhanced methotrexate-induced apoptosis in Raji cells

    International Nuclear Information System (INIS)

    B-cell lymphoma 2 (Bcl-2) is an important member of the Bcl-2 family of proteins that regulate the induction of apoptosis. This study aims to investigate whether Bcl-2 small interfering RNA (siRNA) combined with miR-15a oligonucleotides (ODN) could enhance methotrexate (MTX)-induced apoptosis in Raji cells. Chemically synthesized miR-15a ODN and Bcl-2 siRNA were transfected in Raji cells by using a HiPerFect Transfection Reagent and then combined with MTX. Expression levels of Bcl-2 protein were detected by Western blot. Cell proliferation was determined by CCK8 assay. The rate of cell apoptosis was determined by Annexin V/PI double staining. The morphology of apoptotic cells was observed by Hoechst-33 258 staining. After the cells were transfected with miR-15a ODN combined with Bcl-2 siRNA, Bcl-2 protein levels were evidently decreased. CCK8 assay showed that cell proliferation was significantly decreased and was significantly lower in miR-15a ODN combined with Bcl-2 siRNA plus MTX group than in miR-15a ODN with methotrexate group, Bcl-2 siRNA with MTX group, and single MTX group (P<0.05). Hoechst 33258 staining revealed numerous apoptotic cells. AnnexinV/PI double staining showed that the apoptotic rates were (13.13±1.60)%, (34.47±2.96)%, (32.87±3.48)%, and (45.47±2.16)% in MTX, Bcl-2 siRNA plus MTX, miR-15a ODN plus MTX, and miR-15a ODN combined with Bcl-2 siRNA plus MTX groups, respectively. Among these groups, the apoptotic rate of miR-15a ODN combined with Bcl-2 siRNA plus MTX group was the highest; this apoptotic rate was also significantly different from that of miR-15a ODN or Bcl-2 siRNA plus MTX (P<0.05). Bcl-2 siRNA combined with miR-15a ODN could enhance MTX-induced apoptosis in Raji cells. Bcl-2 siRNA and miR-15a combined with MTX may be a useful approach to improve the treatment effects on lymphoma

  4. Prometaphase arrest-dependent phosphorylation of Bcl-2 family proteins and activation of mitochondrial apoptotic pathway are associated with 17α-estradiol-induced apoptosis in human Jurkat T cells.

    Science.gov (United States)

    Han, Cho Rong; Jun, Do Youn; Kim, Yoon Hee; Lee, Ji Young; Kim, Young Ho

    2013-10-01

    In Jurkat T cell clone (JT/Neo), G2/M arrest, apoptotic sub-G1 peak, mitochondrial membrane potential (Δψm) loss, and TUNEL-positive DNA fragmentation were induced following exposure to 17α-estradiol (17α-E2), whereas none of these events (except for G2/M arrest) were induced in Jurkat cells overexpressing Bcl-2 (JT/Bcl-2). Under these conditions, phosphorylation at Thr161 and dephosphorylation at Tyr15 of Cdk1, upregulation of cyclin B1 level, histone H1 phosphorylation, Cdc25C phosphorylation at Thr-48, Bcl-2 phosphorylation at Thr-56 and Ser-70, Mcl-1 phosphorylation, and Bim phosphorylation were detected in the presence of Bcl-2 overexpression. However, the 17α-E2-induced upregulation of Bak levels, activation of Bak, activation of caspase-3, and PARP degradation were abrogated by Bcl-2 overexpression. In the presence of the G1/S blocking agent hydroxyurea, 17α-E2 failed to induce G2/M arrest and all apoptotic events including Cdk1 activation and phosphorylation of Bcl-2, Mcl-1 and Bim. The 17α-E2-induced phosphorylation of Bcl-2 family proteins and mitochondrial apoptotic events were suppressed by a Cdk1 inhibitor but not by aurora A and aurora B kinase inhibitors. Immunofluorescence microscopic analysis showed that an aberrant bipolar microtubule array, incomplete chromosome congression at the metaphase plate, and prometaphase arrest, which was reversible, were the underlying factors for 17α-E2-induced mitotic arrest. The in vitro microtubule polymerization assay showed that 17α-E2 could directly inhibit microtubule formation. These results show that the apoptogenic activity of 17α-E2 was due to the impaired mitotic spindle assembly causing prometaphase arrest and prolonged Cdk1 activation, the phosphorylation of Bcl-2, Mcl-1 and Bim, and the activation of Bak and mitochondria-dependent caspase cascade. PMID:23707954

  5. Transformer 2β and miR-204 regulate apoptosis through competitive binding to 3' UTR of BCL2 mRNA.

    Science.gov (United States)

    Kuwano, Y; Nishida, K; Kajita, K; Satake, Y; Akaike, Y; Fujita, K; Kano, S; Masuda, K; Rokutan, K

    2015-05-01

    RNA-binding proteins and microRNAs are potent post-transcriptional regulators of gene expression. Human transformer 2β (Tra2β) is a serine/arginine-rich-like protein splicing factor and is now implicated to have wide-ranging roles in gene expression as an RNA-binding protein. RNA immunoprecipitation (RIP) with an anti-Tra2β antibody and microarray analysis identified a subset of Tra2β-associated mRNAs in HCT116 human colon cancer cells, many of which encoded cell death-related proteins including Bcl-2 (B-cell CLL/lymphoma 2). Tra2β knockdown in HCT116 cells decreased Bcl-2 expression and induced apoptosis. Tra2β knockdown accelerated the decay of BCL2α mRNA that encodes Bcl-2 and full-length 3' UTR, while it did not affect the stability of BCL2β mRNA having a short, alternatively spliced 3' UTR different from BCL2α 3' UTR. RIP assays with anti-Tra2β and anti-Argonaute 2 antibodies, respectively, showed that Tra2β bound to BCL2α 3' UTR, and that Tra2β knockdown facilitated association of miR-204 with BCL2α 3' UTR. The consensus sequence (GAA) for Tra2β-binding lies within the miR-204-binding site of BCL2 3' UTR. Mutation of the consensus sequence canceled the binding of Tra2β to BCL2 3' UTR without disrupting miR-204-binding to BCL2 3' UTR. Transfection of an anti-miR-204 or introduction of three-point mutations into the miR-204-binding site increased BCL2 mRNA and Bcl-2 protein levels. Inversely, transfection of precursor miR-204 reduced their levels. Experiments with Tra2β-silenced or overexpressed cells revealed that Tra2β antagonized the effects of miR-204 and upregulated Bcl-2 expression. Furthermore, TRA2β mRNA expression was significantly upregulated in 22 colon cancer tissues compared with paired normal tissues and positively correlated with BCL2 mRNA expression. Tra2β knockdown in human lung adenocarcinoma cells (A549) increased their sensitivity to anticancer drugs. Taken together, our findings suggest that Tra2β regulates apoptosis by

  6. Allitridi induces apoptosis by affecting Bcl-2 expression and caspase-3 activity in human gastric cancer cells

    Institute of Scientific and Technical Information of China (English)

    Hong LAN; You-yong LU

    2004-01-01

    AIM: To investigate the mechanism of allitridi-induced apoptosis in human gastric cancer cell line BGC823.METHODS: Growth inhibition by allitridi was analyzed using cell growth curve and MTT assay. Apoptotic cells were detected using staining with Hoechst 33342, and confirmed by flow cytometric analysis and DNA fragmentation analysis. The protein expression affected by allitridi was determined using Western blot. The activity of caspase-3 was measured using a fluorescence assay. RESULTS: Allitridi induced apoptosis, and then inhibited cells proliferation in human gastric cancer cell line BGC823. The protein level of Bcl-2 was decreased dramatically,while Bax and p53 were not significantly affected by allitridi. The expression and activity of caspase-3 started to increase after allitridi treatment for 72 h. CONCLUSION: Allitridi induced apoptosis through down-regulation of Bcl-2, and increased caspase-3 expression and its activity.

  7. Xanthorrhizol induced DNA fragmentation in HepG2 cells involving Bcl-2 family proteins

    Energy Technology Data Exchange (ETDEWEB)

    Tee, Thiam-Tsui, E-mail: thiamtsu@yahoo.com [School of Biosciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Cheah, Yew-Hoong [School of Biosciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Bioassay Unit, Herbal Medicine Research Center, Institute for Medical Research, Jalan Pahang, Kuala Lumpur (Malaysia); Meenakshii, Nallappan [Biology Department, Faculty of Science, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia); Mohd Sharom, Mohd Yusof; Azimahtol Hawariah, Lope Pihie [School of Biosciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia)

    2012-04-20

    Highlights: Black-Right-Pointing-Pointer We isolated xanthorrhizol, a sesquiterpenoid compound from Curcuma xanthorrhiza. Black-Right-Pointing-Pointer Xanthorrhizol induced apoptosis in HepG2 cells as observed using SEM. Black-Right-Pointing-Pointer Apoptosis in xanthorrhizol-treated HepG2 cells involved Bcl-2 family proteins. Black-Right-Pointing-Pointer DNA fragmentation was observed in xanthorrhizol-treated HepG2 cells. Black-Right-Pointing-Pointer DNA fragmentation maybe due to cleavage of PARP and DFF45/ICAD proteins. -- Abstract: Xanthorrhizol is a plant-derived pharmacologically active sesquiterpenoid compound isolated from Curcuma xanthorrhiza. Previously, we have reported that xanthorrhizol inhibited the proliferation of HepG2 human hepatoma cells by inducing apoptotic cell death via caspase activation. Here, we attempt to further elucidate the mode of action of xanthorrhizol. Apoptosis in xanthorrhizol-treated HepG2 cells as observed by scanning electron microscopy was accompanied by truncation of BID; reduction of both anti-apoptotic Bcl-2 and Bcl-X{sub L} expression; cleavage of PARP and DFF45/ICAD proteins and DNA fragmentation. Taken together, these results suggest xanthorrhizol as a potent antiproliferative agent on HepG2 cells by inducing apoptosis via Bcl-2 family members. Hence we proposed that xanthorrhizol could be used as an anti-liver cancer drug for future studies.

  8. Xanthorrhizol induced DNA fragmentation in HepG2 cells involving Bcl-2 family proteins

    International Nuclear Information System (INIS)

    Highlights: ► We isolated xanthorrhizol, a sesquiterpenoid compound from Curcuma xanthorrhiza. ► Xanthorrhizol induced apoptosis in HepG2 cells as observed using SEM. ► Apoptosis in xanthorrhizol-treated HepG2 cells involved Bcl-2 family proteins. ► DNA fragmentation was observed in xanthorrhizol-treated HepG2 cells. ► DNA fragmentation maybe due to cleavage of PARP and DFF45/ICAD proteins. -- Abstract: Xanthorrhizol is a plant-derived pharmacologically active sesquiterpenoid compound isolated from Curcuma xanthorrhiza. Previously, we have reported that xanthorrhizol inhibited the proliferation of HepG2 human hepatoma cells by inducing apoptotic cell death via caspase activation. Here, we attempt to further elucidate the mode of action of xanthorrhizol. Apoptosis in xanthorrhizol-treated HepG2 cells as observed by scanning electron microscopy was accompanied by truncation of BID; reduction of both anti-apoptotic Bcl-2 and Bcl-XL expression; cleavage of PARP and DFF45/ICAD proteins and DNA fragmentation. Taken together, these results suggest xanthorrhizol as a potent antiproliferative agent on HepG2 cells by inducing apoptosis via Bcl-2 family members. Hence we proposed that xanthorrhizol could be used as an anti-liver cancer drug for future studies.

  9. Effect of low dose radiation on P53 and Bcl-2 protein expression in spermatogenic cells of mouse testis

    International Nuclear Information System (INIS)

    Objective: To investigate the effect of low dose radiation (LDR) with different dose of X-rays on P53 and Bcl-2 protein expression in spermatogenic cells of male Kunming mouse testis. Methods: The relationships between time-effect and dose-effect of P53 and Bcl-2 protein expression positive rate in spermatogenic cells of mouse testis after LDR with different dose of X-rays were studied with immunohistochemical technique (SABC). Results: P53 and Bcl-2 protein expressed in spermatogonia and spermatocytes in varying degrees, the positive rate of spermatogonia was obviously superior to that of spermatocytes. With the increase of irradiation dose, the expression of P53 protein showed a increasing tendency, however, the P53 protein expression of spermatozoa scarcely occurred after LDR. Bcl-2 protein was primarily expressed in spermatozoa. With the increase of irradiation dose, the positive rate of Bcl-2 protein expression showed a downregulated tendency. However, the Bcl-2 protein expression of spermatogonia and spermatocytes scarcely occurred after LDR. Conclusion: The expressions of P53 and Bcl-2 may have regular changes in mouse testis induced by LDR, which may provide a experimental evidence for the mechanism study of spermatogonic cell apoptosis induced selectively by ionizing radiation

  10. Korean Red Ginseng protects endothelial cells from serum-deprived apoptosis by regulating Bcl-2 family protein dynamics and caspase S-nitrosylation

    OpenAIRE

    Kim, Young-Mi; Kim, Jung Hwan; Kwon, Hyuk Min; Lee, Dong Heon; Won, Moo-Ho; Kwon, Young-Guen; Kim, Young-Myeong

    2013-01-01

    Korean Red Ginseng extract (KRGE) is a traditional herbal medicine utilized to prevent endothelium dysfunction in the cardiovascular system; however, its underlying mechanism has not been clearly elucidated. We here examined the pharmacological effect and molecular mechanism of KRGE on apoptosis of human umbilical vein endothelial cells (HUVECs) in a serum-deprived apoptosis model. KRGE protected HUVECs from serum-deprived apoptosis by inhibiting mitochondrial cytochrome c release and caspase...

  11. Atherosclerosis-Associated Endothelial Cell Apoptosis by MiR-429-Mediated Down Regulation of Bcl-2

    Directory of Open Access Journals (Sweden)

    Tao Zhang

    2015-10-01

    Full Text Available Background/Aims: Endothelial cell injury and subsequent apoptosis play a key role in the development and pathogenesis of atherosclerosis, which is hallmarked by dysregulated lipid homeostasis, aberrant immunity and inflammation, and plaque-instability-associated coronary occlusion. Nevertheless, our understanding of the mechanisms underlying endothelial cell apoptosis is still limited. MicroRNA-429 (miR-29 is a known cancer suppressor that promotes cancer cell apoptosis. However, it is unknown whether miR-429 may be involved in the development of atherosclerosis through similar mechanisms. We addressed these questions in the current study. Methods: We examined the levels of endothelial cell apoptosis in ApoE (-/- mice suppled with high-fat diet (HFD, a mouse model for atherosclerosis (simplified as HFD mice. We analyzed the levels of anti-apoptotic protein Bcl-2 and the levels of miR-429 in the purified CD31+ endothelial cells from mouse aorta. Prediction of the binding between miR-429 and 3'-UTR of Bcl-2 mRNA was performed by bioinformatics analyses and confirmed by a dual luciferase reporter assay. The effects of miR-429 were further analyzed in an in vitro model using oxidized low-density lipoprotein (ox-LDL-treated human aortic endothelial cells (HAECs. Results: HFD mice developed atherosclerosis in 12 weeks, while the control ApoE (-/- mice that had received normal diet (simplified as NOR mice did not. HFD mice had significantly lower percentage of endothelial cells and significantly higher percentage of mesenchymal cells in the aorta than NOR mice. Significantly higher levels of endothelial cell apoptosis were detected in HFD mice, resulting from decreases in Bcl-2 protein, but not mRNA. The decreases in Bcl-2 in endothelial cells were due to increased levels of miR-429, which suppressed the translation of Bcl-2 mRNA via 3'-UTR binding. These in vivo findings were reproduced in vitro on ox-LDL-treated HAECs. Conclusion: Atherosclerosis

  12. BCL2 protein expression in follicular lymphomas with t(14;18) chromosomal translocations.

    Science.gov (United States)

    Masir, Noraidah; Campbell, Lisa J; Goff, Lindsey K; Jones, Margaret; Marafioti, Teresa; Cordell, Jacqueline; Clear, Andrew J; Lister, T Andrew; Mason, David Y; Lee, Abigail M

    2009-03-01

    The t(14;18)(q32;q21) chromosomal translocation induces BCL2 protein overexpression in most follicular lymphomas. However the expression of BCL2 is not always homogeneous and may demonstrate a variable degree of heterogeneity. This study analysed BCL2 protein expression pattern in 33 cases of t(14;18)-positive follicular lymphomas using antibodies against two different epitopes (i.e. the widely used antibody BCL2/124 and an alternative antibody E17). 16/33 (49%) cases demonstrated strong BCL2 expression. In 10/33 (30%) cases, BCL2 expression was heterogeneous and in some of these, its loss appeared to be correlated with cell proliferation, as indicated by Ki67 expression. Double immunofluorescence labelling confirmed an inverse BCL2/Ki67 relationship, where in 24/28 (86%) cases cellular expression of BCL2 and Ki67 was mutually exclusive. In addition, seven BCL2 'pseudo-negative' cases were identified in which immunostaining was negative with antibody BCL2/124, but positive with antibody E17. Genomic DNA sequencing of these 'pseudo-negative' cases demonstrated eleven mutations in four cases and nine of these were missense mutations. It can be concluded that in follicular lymphomas, despite carrying the t(14;18) translocations, BCL2 protein expression may be heterogeneous and loss of BCL2 could be related to cell proliferation. Secondly, mutations in translocated BCL2 genes appear to be common and may cause BCL2 pseudo-negative immunostaining. PMID:19120369

  13. Intermittent hypoxia attenuates ischemia/reperfusion induced apoptosis in cardiac myocytes via regulating Bcl-2/Bax expression

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Intermittent hypoxia has been shown to provide myocardial protection against ishemia/reperfusion-induced injury.Cardiac myocyte loss through apoptosis has been reported in ischemia/reperfusion injury. Our aim was to investigate whether intermittent hypoxia could attenuate ischemia/reperfusion-induced apoptosis in cardiac myocytes and its potential mechanisms. Adult male Sprague-Dawley rats were exposed to hypoxia simulated 5000 m in a hypobaric chamber for 6 h/day, lasting 42 days. Normoxia group rats were kept under normoxic conditions. Isolated perfused hearts from both groups were subjected to 30 min of global ischemia followed by 60 min reperfusion.Incidence of apoptosis in cardiac myocytes was determined by terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) and DNA agarose gel electrophoresis. Expressions of apoptosis related proteins,Bax and Bcl-2, in cytosolic and membrane fraction were detected by Western Blotting. After ischemia/reperfusion,enhanced recovery of cardiac function was observed in intermittent hypoxia hearts compared with normoxia group.Ischemia/reperfusion-induced apoptosis, as evidenced by TUNEL-positive nuclei and DNA fragmentation, was significantly reduced in intermittent hypoxia group compared with normoxia group. After ischemia/reperfusion,expression of Bax in both cytosolic and membrane fractions was decreased in intermittent hypoxia hearts compared with normoxia group. Although ischemia/reperfusion did not induce changes in the level of Bcl-2 expression in cytosolic fraction between intermittent hypoxia and normoxia groups, the expression of Bcl-2 in membrane fraction was upregulated in intermittent hypoxia group compared with normoxia group. These results indicated that the cardioprotection of intermittent hypoxia against ischemia/reperfusion injury appears to be in part due to reduce myocardial apoptosis. Intermittent hypoxia attenuated ischemia/reperfusion-induced apoptosis via increasing the ratio of Bcl

  14. Nature promises new anticancer agents: Interplay with the apoptosis-related BCL2 gene family.

    Science.gov (United States)

    Christodoulou, Maria-Ioanna; Kontos, Christos K; Halabalaki, Maria; Skaltsounis, Alexios-Leandros; Scorilas, Andreas

    2014-03-01

    Natural products display special attributes in the treatment and prevention of a variety of human disorders including cancer. Their therapeutic capacities along with the fact that nature comprises a priceless pool of new compounds have attracted the interest of researchers worldwide. A significant number of organic compounds from terrestrial and marine organisms exhibit anticancer properties as attested by both in vitro and in vivo studies. Emerging evidence supporting the antineoplastic activity of natural compounds has rendered them promising agents in the fight against cancer. As a result, numerous natural compounds or their derivatives have entered clinical practice and are currently in the forefront of chemotherapeutics, showing beneficial effects for cancer patients. Induction of apoptosis seems to be the major mechanism of action induced by these natural agents in the race against cancer. This is mainly achieved through modulations of the expression of B-cell CLL/lymphoma 2 (BCL2) family members. These molecules appear to be the pivotal players determining cellular fate. In the current review, we provide a comprehensive overview of the major alterations in the gene and/or protein levels of BCL2-family members evoked in cancer cells after treatment with a gamut of natural compounds. The data cited suggest the need for exploitation of newly discovered natural products that, along with the improvement of currently employed chemotherapeutics, will significantly enrich the anticancer armamentarium. PMID:23848203

  15. Recombinant human erythropoietin suppresses endothelial cell apoptosis and reduces the ratio of Bax to Bcl-2 proteins in the aortas of apolipoprotein E-deficient mice

    OpenAIRE

    Warren, Jeffrey S.; Zhao, Ying; Yung, Raymond; Desai, Anjali

    2011-01-01

    Recent clinical trials have raised concern that therapy with recombinant human erythropoietin (EPO) may increase cardiovascular disease risk, event rate, and mortality. Endothelial cell (EC) apoptosis has been implicated in both atherogenesis as well as in the destabilization and rupture of atheromatous plaques.

  16. The C. elegans protein CEH-30 protects male-specific neurons from apoptosis independently of the Bcl-2 homolog CED-9

    OpenAIRE

    Schwartz, Hillel T.; Horvitz, H Robert

    2007-01-01

    The developmental control of apoptosis is fundamental and important. We report that the Caenorhabditis elegans Bar homeodomain transcription factor CEH-30 is required for the sexually dimorphic survival of the male-specific CEM (cephalic male) sensory neurons; the homologous cells of hermaphrodites undergo programmed cell death. We propose that the cell-type-specific anti-apoptotic gene ceh-30 is transcriptionally repressed by the TRA-1 transcription factor, the terminal regulator of sexual i...

  17. Effect of soluble CD44 molecule on the expression of apoptosis regulatory protein bcl-2 associated death factor bad in human trabecular meshwork cell%可溶性CD44分子对人眼小梁网细胞凋亡调节蛋白bcl-2相关死亡因子bad表达的影响

    Institute of Scientific and Technical Information of China (English)

    梁宗宝; 吴瑜瑜; 郭茂生

    2012-01-01

    亡因子bad蛋白的表达.%Background Researches demonstrated that the levels of soluble CD44 (sCD44)molecule in aqueous is significantly higher in primary open-angle glaucomous(POAG) eye than normal eye,but how the sCD44 would affect the expression of apoptosis protein in trabecular meshwork cells is below understanding. Objective The present study was to investigate the effect of sCD44 on the expression of regulatory proteins bcl-2 associated death factor bad in trabecular meshwork cells in the patients with POAG. Methods Human scleral tissue with trabecular meshwork were obtained from POAG patients during the surgery.The trabecular meshwork cells were primarily cultured by explant culture method and identified by immunochemistry.The third generation of cells were incubated with free-serum DMEM/F12 medium added differnt dosages of sCD44 (0,1,5,10,25,50 mg/L) for 48 hours.The expression of bad protein in cultured cells was detected using cell counting kit-8 (CCK-8) as the absorbance values at 490 nm(A,90 value),and the bad protein level in cultured cells was assayed by ELISA. Results The cultured cells showed the positive response for laminin ( LM ),neuron specific enolase ( NSE ),fibronectin ( FN ) monoclonal antibodies.The CCK-8 assay showed that the A490 values of the trabecular meshwork cells in 0,1,5,10,25,50 μg/L of sCD44 groups were 0.2460±0.0019,0.1874±0.0015,0.1570±0.0016,0.1302±0.0019,0.1084±0.0018,0.0940±0.0020 respectively with a statistically significant difference among the 6 groups( F =14.922,P =0.000 ),and the A490 values in various dosages of sCD44 groups were significantly lower than the 0 μg/L sCD44 group (P=0.013,0.008,0.011,0.005,0.004).The ELISA assay showed that bad protein levels in 0,1,5,10,25,50 μg/L of sCD44 groups were ( 114.8461 ± 2.9560 ),( 137.8270 ± 2.4259 ),( 161.4194 ± 3.7381 ),( 170.9453 ± 3.2006 ),( 221.2252 ±4.3738 ),( 324.6167±4.4220) ng/L,showing a total difference among them ( F =16.610,P =0.000 ),and the bad protein levels in various dosages of sCD44

  18. Sheeppox Virus SPPV14 Encodes a Bcl-2-Like Cell Death Inhibitor That Counters a Distinct Set of Mammalian Proapoptotic Proteins

    OpenAIRE

    Okamoto, Toru; Campbell, Stephanie; Mehta, Ninad; Thibault, John; Colman, Peter M.; Barry, Michele; Huang, David C. S.; Kvansakul, Marc

    2012-01-01

    Many viruses express inhibitors of programmed cell death (apoptosis), thereby countering host defenses that would otherwise rapidly clear infected cells. To counter this, viruses such as adenoviruses and herpesviruses express recognizable homologs of the mammalian prosurvival protein Bcl-2. In contrast, the majority of poxviruses lack viral Bcl-2 (vBcl-2) homologs that are readily identified by sequence similarities. One such virus, myxoma virus, which is the causative agent of myxomatosis, e...

  19. Curcumin significantly enhances dual PI3K/Akt and mTOR inhibitor NVP-BEZ235-induced apoptosis in human renal carcinoma Caki cells through down-regulation of p53-dependent Bcl-2 expression and inhibition of Mcl-1 protein stability.

    Directory of Open Access Journals (Sweden)

    Bo Ram Seo

    Full Text Available The PI3K/Akt and mTOR signaling pathways are important for cell survival and growth, and they are highly activated in cancer cells compared with normal cells. Therefore, these signaling pathways are targets for inducing cancer cell death. The dual PI3K/Akt and mTOR inhibitor NVP-BEZ235 completely inhibited both signaling pathways. However, NVP-BEZ235 had no effect on cell death in human renal carcinoma Caki cells. We tested whether combined treatment with natural compounds and NVP-BEZ235 could induce cell death. Among several chemopreventive agents, curcumin, a natural biologically active compound that is extracted from the rhizomes of Curcuma species, markedly induced apoptosis in NVP-BEZ235-treated cells. Co-treatment with curcumin and NVP-BEZ235 led to the down-regulation of Mcl-1 protein expression but not mRNA expression. Ectopic expression of Mcl-1 completely inhibited curcumin plus NVP-NEZ235-induced apoptosis. Furthermore, the down-regulation of Bcl-2 was involved in curcumin plus NVP-BEZ235-induced apoptosis. Curcumin or NVP-BEZ235 alone did not change Bcl-2 mRNA or protein expression, but co-treatment reduced Bcl-2 mRNA and protein expression. Combined treatment with NVP-BEZ235 and curcumin reduced Bcl-2 expression in wild-type p53 HCT116 human colon carcinoma cells but not p53-null HCT116 cells. Moreover, Bcl-2 expression was completely reversed by treatment with pifithrin-α, a p53-specific inhibitor. Ectopic expression of Bcl-2 also inhibited apoptosis in NVP-BE235 plus curcumin-treated cells. In contrast, NVP-BEZ235 combined with curcumin did not have a synergistic effect on normal human skin fibroblasts and normal human mesangial cells. Taken together, combined treatment with NVP-BEZ235 and curcumin induces apoptosis through p53-dependent Bcl-2 mRNA down-regulation at the transcriptional level and Mcl-1 protein down-regulation at the post-transcriptional level.

  20. Bcl-2 protein expression is associated with p27 and p53 protein expressions and MIB-1 counts in breast cancer

    Directory of Open Access Journals (Sweden)

    Nishizaki Takashi

    2006-07-01

    Full Text Available Abstract Background Recent experimental studies have shown that Bcl-2, which has been established as a key player in the control of apoptosis, plays a role in regulating the cell cycle and proliferation. The aim of this study was to investigate the relationship between Bcl-2 and p27 protein expression, p53 protein expression and the proliferation activity as defined by the MIB-1 counts. The prognostic implication of Bcl-2 protein expression in relation to p27 and p53 protein expressions and MIB-1 counts for breast cancer was also evaluated. Methods The immunohistochemical expression of Bcl-2 protein was evaluated in a series of 249 invasive ductal carcinomas of the breast, in which p27 and p53 protein expressions and MIB-1 counts had been determined previously. Results The Bcl-2 protein expression was found to be decreased in 105 (42% cases. A decreased Bcl-2 protein expression was significantly correlated with a nuclear grade of III, a negative estrogen receptor, a decreased p27 protein expression, a positive p53 protein expression, positive MIB-1 counts and a positive HER2 protein expression. The incidence of a nuclear grade of III and positive MIB-1 counts increased as the number of abnormal findings of Bcl-2, p27 and p53 protein expressions increased. A univariate analysis indicated a decreased Bcl-2 protein expression to be significantly (p = 0.0089 associated with a worse disease free survival (DFS, while a multivariate analysis indicated the lymph node status and MIB-1 counts to be independently significant prognostic factors for the DFS. Conclusion The Bcl-2 protein expression has a close correlation with p27 and p53 protein expressions and the proliferation activity determined by MIB-1 counts in invasive ductal carcinoma of the breast. The prognostic value of Bcl-2 as well as p27 and p53 protein expressions was dependent on the proliferation activity in breast cancer.

  1. Quercetin induces apoptosis by activating caspase-3 and regulating Bcl-2 and cyclooxygenase-2 pathways in human HL-60 cells

    Institute of Scientific and Technical Information of China (English)

    Guomin Niu; Songmei Yin; Shuangfeng Xie; Yiqing Li; Danian Nie; Liping Ma; Xiuju Wang; Yudan Wu

    2011-01-01

    Quercetin is one of the naturally occurring dietary flavo-nol compounds. It is present abundantly in plants and has chemopreventive and anticancer effects. To investigate its anticancer mechanism, we examined the activity of quercetin against acute leukemia cell line, HL-60. Our results showed that quercetin inhibited cell proliferation and induced apoptosis in a time- and dose-dependent manner. Furthermore, quercetin down-regulated the expression of anti-apoptosis protein Bcl-2 and up-regulated the expression of pro-apoptosis protein Bax. Caspase-3 was also activated by quercetin, which started a caspase-3-depended mitochodrial pathway to induce apoptosis. It was also found that quercetin inhibited the expression of the cycloocygenase-2 (Cox-2) mRNA and Cox-2 protein. Taken together, these findings suggested that quercetin induces apoptosis in a caspase-3-dependent pathway by inhibiting Cox-2 expression and regulates the expression of downstream apoptotic components, including Bcl-2 and Bax. Quercetin can be a potent and promising medicine which might be safely used in leukemia therapy.

  2. Extracellular BCL2 Proteins Are Danger-Associated Molecular Patterns That Reduce Tissue Damage in Murine Models of Ischemia-Reperfusion Injury

    Science.gov (United States)

    Iwata, Akiko; Morgan-Stevenson, Vicki; Schwartz, Barbara; Liu, Li; Tupper, Joan; Zhu, Xiaodong

    2010-01-01

    Background Ischemia-reperfusion (I/R) injury contributes to organ dysfunction in a variety of clinical disorders, including myocardial infarction, stroke, organ transplantation, and hemorrhagic shock. Recent investigations have demonstrated that apoptosis as an important mechanism of cell death leading to organ dysfunction following I/R. Intracellular danger-associated molecular patterns (DAMPs) released during cell death can activate cytoprotective responses by engaging receptors of the innate immune system. Methodology/Principal Findings Ischemia was induced in the mouse hind limb by tourniquet or in the heart by coronary artery ligation. Reperfusion injury of skeletal or cardiac muscle was markedly reduced by intraperitoneal or subcutaneous injection of recombinant human (rh)BCL2 protein or rhBCL2-related protein A1 (BCL2A1) (50 ng/g) given prior to ischemia or at the time of reperfusion. The cytoprotective activity of extracellular rhBCL2 or rhBCL2A1 protein was mapped to the BH4 domain, as treatment with a mutant BCL2 protein lacking the BH4 domain was not protective, whereas peptides derived from the BH4 domain of BCL2 or the BH4-like domain of BCL2A1 were. Protection by extracellular rhBCL2 or rhBCL2A1 was associated with a reduction in apoptosis in skeletal and cardiac muscle following I/R, concomitant with increased expression of endogenous mouse BCL2 (mBCL2) protein. Notably, treatment with rhBCL2A1 protein did not protect mice deficient in toll-like receptor-2 (TLR2) or the adaptor protein, myeloid differentiation factor-88 (MyD88). Conclusions/Significance Treatment with cytokine-like doses of rhBCL2 or rhBCL2A1 protein or BH4-domain peptides reduces apoptosis and tissue injury following I/R by a TLR2-MyD88-dependent mechanism. These findings establish a novel extracellular cytoprotective activity of BCL2 BH4-domain proteins as potent cytoprotective DAMPs. PMID:20161703

  3. Boron neutron capture therapy induces apoptosis of glioma cells through Bcl-2/Bax

    Directory of Open Access Journals (Sweden)

    Mao Xinggang

    2010-12-01

    Full Text Available Abstract Background Boron neutron capture therapy (BNCT is an alternative treatment modality for patients with glioma. The aim of this study was to determine whether induction of apoptosis contributes to the main therapeutic efficacy of BNCT and to compare the relative biological effect (RBE of BNCT, γ-ray and reactor neutron irradiation. Methods The neutron beam was obtained from the Xi'an Pulsed Reactor (XAPR and γ-rays were obtained from [60Co] γ source of the Fourth Military Medical University (FMMU in China. Human glioma cells (the U87, U251, and SHG44 cell lines were irradiated by neutron beams at the XAPR or [60Co] γ-rays at the FMMU with different protocols: Group A included control nonirradiated cells; Group B included cells treated with 4 Gy of [60Co] γ-rays; Group C included cells treated with 8 Gy of [60Co] γ-rays; Group D included cells treated with 4 Gy BPA (p-borono-phenylalanine-BNCT; Group E included cells treated with 8 Gy BPA-BNCT; Group F included cells irradiated in the reactor for the same treatment period as used for Group D; Group G included cells irradiated in the reactor for the same treatment period as used for Group E; Group H included cells irradiated with 4 Gy in the reactor; and Group I included cells irradiated with 8 Gy in the reactor. Cell survival was determined using the 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium (MTT cytotoxicity assay. The morphology of cells was detected by Hoechst33342 staining and transmission electron microscope (TEM. The apoptosis rate was detected by flow cytometer (FCM. The level of Bcl-2 and Bax protein was measured by western blot analysis. Results Proliferation of U87, U251, and SHG44 cells was much more strongly inhibited by BPA-BNCT than by irradiation with [60Co] γ-rays (P 60Co] γ-rays (P P Conclusions Compared with ��-ray and reactor neutron irradiation, a higher RBE can be achieved upon treatment of glioma cells with BNCT. Glioma cell apoptosis induced by

  4. THE OVEREXPRESSION OF APOPTOSIS -RELATED GENES OF P53 AND BCL-2 IN CERVICAL CARCINOMA

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective To investigate the significance of overexpression of P53 and bcl-2 protein in carcinogenesis of cervix. Methods 10 cases of cervical intraepithelial neoplasis(CIN) and 57 cases of invasive cancer were investigated with immunohistochemistry technique. Results The overexpresion of P53 protein in CIN and cervical cancer was significantly higher than that of control, respectively (P<0.01). But there was no significant difference between CIN and cervical cancer(P>0. 05). The immunoreactivity of bcl-2 in CIN was much more higher than that of control (P<0.05). The positive rate and immunoreactivity of bcl-2 in cervical carcinoma were both remarkably higher than those of control (P<0. 01) ,but there was no significant difference between CIN and cervical carcinoma (P>0. 05). It was also found that there was a remarkably positive correlation between the overexpression of bcl-2 and P53 (P<0.01). Conclusion Because of the loss of wtP53 function,the expression of bcl-2 can not be down-reguated,which is associated with the pathogenesis and development of cervical carcinoma.

  5. Induction of apoptosis and bcl-2 expression in acute lymphoblastic leukaemia and non-Hodgkin's lymphoma in children.

    Science.gov (United States)

    Pituch-Noworolska, A; Hajto, B; Balwierz, W; Klus, K

    2001-01-01

    bcl-2 expression is associated with the expression of the multidrug resistance molecule (p-gp) and the resistance of leukaemia cells to the induction of apoptosis. The activity of p-gp is the main mechanism of resistance of leukaemia cells to chemotherapy. This study assessed the induction of apoptosis of acute lymphoblastic leukaemia (ALL) and non-Hodgkin's lymphoma (NHL) blastic cells following in vitro treatment with dexamethasone (DXM), vincristine (VCR), and tumour necrosis factor (TNF) in relation to the expression of bcl-2 and p-gp. Common ALL (cALL; n = 24 patients), common ALL with co-expression of myeloid antigens (cALL + My; n = 9), ALL-T (n = 9), and NHL [n = 6 (T type, n = 2; B type, n = 4)] were included. The expression of bcl-2 and p-gp and apoptosis were assayed by flow cytometry. Spontaneous apoptosis was low ( 8%) in NHL and cALL + My. A high frequency of bcl-2 expression was noted in cALL and cALL + My. A high frequency of p-gp expression was observed in cALL + My, ALL-T, and NHL. There was a reverse association between bcl-2 expression and spontaneous apoptosis. DXM-induced apoptosis was observed in 52.63%, TNF-induced in 42.85%, VCR-induced in 36.36%, and GM-CSF-induced in 33.3% of leukaemia and lymphoma cases. DXM and GM-CSF-driven apoptosis was reversibly associated with bcl-2-expression (bcl-2-dependent mechanism). VCR and TNF-driven apoptosis was not associated with bcl-2 expression, suggesting a different, bcl-2-independent, mechanism(s) of its induction. The in vitro induction of apoptosis was not associated with expression of p-gp. PMID:11855781

  6. Upregulation of Bax and Bcl-2 following prenatal cocaine exposure induces apoptosis in fetal rat brain

    OpenAIRE

    Xiao, DaLiao; Zhang, Lubo

    2008-01-01

    Cocaine abuse during pregnancy has been associated with numerous adverse perinatal outcomes. Aims: The present study was to determine whether prenatal cocaine exposure induced apoptosis and the possible role of Bcl-2 family genes in the programming cell death in fetal rat brain. Main methods: Pregnant rats were treated with cocaine subcutaneously (30 & 60 mg/kg/day) from day 15 to 21 of gestation. Then the fetal and maternal brains were isolated. Key findings: Cocaine produced a dose-dependen...

  7. Upregulation of Bax and Bcl-2 following prenatal cocaine exposure induces apoptosis in fetal rat brain

    OpenAIRE

    DaLiao Xiao, Lubo Zhang

    2008-01-01

    Cocaine abuse during pregnancy has been associated with numerous adverse perinatal outcomes. Aims: The present study was to determine whether prenatal cocaine exposure induced apoptosis and the possible role of Bcl-2 family genes in the programming cell death in fetal rat brain. Main methods: Pregnant rats were treated with cocaine subcutaneously (30 & 60 mg/kg/day) from day 15 to 21 of gestation. Then the fetal and maternal brains were isolated. Key findings: Cocaine produced a dose-depe...

  8. Regulation of expression of Bcl-2 protein family member Bim by T cell receptor triggering

    OpenAIRE

    Sandalova, Elena; Wei, Cheng-Hong; Masucci, Maria G.; Levitsky, Victor

    2004-01-01

    Bim, a proapoptotic BH3-only member of the Bcl-2 protein family, is required for central and peripheral deletion of T lymphocytes. Mechanisms regulating Bim activity in T cells remain poorly understood. We show that expression of Bim is up-regulated in human T cells after polyclonal or specific T cell receptor triggering. Induction of Bim was affected by the agonistic potency of MHC:peptide ligands. Peptides that failed to induce Bim expression, failed to induce apoptosis in specific T cells,...

  9. Associations of MMP-2, BAX, and Bcl-2 mRNA and Protein Expressions with Development of Atrial Fibrillation.

    Science.gov (United States)

    Diao, Shu-Ling; Xu, Hui-Pu; Zhang, Bei; Ma, Bao-Xin; Liu, Xian-Liang

    2016-01-01

    BACKGROUND To examine changes of mRNA and protein expressions of MMP-2, Bcl-2, and BAX in atrial fibrillation (AF) patients, and investigate the correlations among these 3 biomarkers. MATERIAL AND METHODS Rheumatic heart disease patients (n=158) undergoing cardiac surgical procedures for mitral valve repair or replacement were included as the AF group (n=123), containing paroxysmal AF (n=42), persistent AF (n=36), and permanent AF (n=45). Rheumatic heart disease patients with sinus rhythm (SR) (n=35) were enrolled as the SR group (control group). Immunohistochemistry, Western blot, and real-time polymerase chain reaction (PCR) were applied to detect the protein and mRNA expression levels of MMP-2, Bcl-2, and BAX. Apoptosis was observed with light and electron microscopes and detected by TdT-mediated dUTP nick-end labeling (TUNEL). RESULTS Compared with the SR group, the left atrial diameters (LADs), protein and mRNA expression levels of MMP-2 and BAX, apoptotic index (AI), and Bcl-2/BAX ratio were evidently increased in the 3 AF groups, but protein and mRNA expression levels of Bcl-2 decreased in the AF groups (all P<0.05). Correlation analysis found that MMP-2 protein expression levels was positively correlated with BAX expression, but negatively correlated with Bcl-2 expression levels. CONCLUSIONS Our study results suggest that elevated MMP-2 expression and disturbance balance of Bcl-2/BAX expressions may be associated with the development and maintenance of AF. MMP-2 may be involved in the development of AF through promoting BAX expressions and inhibiting Bcl-2. PMID:27141955

  10. Regulation of osteoclast apoptosis by ubiquitylation of proapoptotic BH3-only Bcl-2 family member Bim

    OpenAIRE

    Akiyama, Toru; Bouillet, Phillippe; Miyazaki, Tsuyoshi; Kadono, Yuho; Chikuda, Hirotaka; Chung, Ung-il; Fukuda, Akira; Hikita, Atsuhiko; Seto, Hiroaki; Okada, Takashi; Inaba, Toshiya; Sanjay, Archana; Baron, Roland; Kawaguchi, Hiroshi; Oda, Hiromi

    2003-01-01

    Osteoclasts (OCs) undergo rapid apoptosis without trophic factors, such as macrophage colony-stimulating factor (M-CSF). Their apoptosis was associated with a rapid and sustained increase in the pro-apoptotic BH3-only Bcl-2 family member Bim. This was caused by the reduced ubiquitylation and proteasomal degradation of Bim that is mediated by c-Cbl. Although the number of OCs was increased in the skeletal tissues of bim–/– mice, the mice exhibited mild osteosclerosis due to reduced bone resorp...

  11. Antiapoptotic Bcl-2 protein as a potential target for cancer therapy: A mini review.

    Science.gov (United States)

    Jagani, Hitesh; Kasinathan, Narayanan; Meka, Sreenivasa Reddy; Josyula, Venkata Rao

    2016-08-01

    Bcl-2, an antiapoptotic protein, is considered as a potential target in cancer treatment since its oncogenic potential has been proven and is well documented. Antisense technology and RNA interference (RNAi) have been used to reduce the expression of the Bcl-2 gene in many types of cancer cells and are effective as adjuvant therapy along with the chemotherapeutic agents. The lack of appropriate delivery systems is considered to be the main hurdle associated with the RNAi. In this review, we discuss the antiapoptotic Bcl-2 protein, its oncogenic potential, and various approaches utilized to target Bcl-2 including suitable delivery systems employed for successful delivery of siRNA. PMID:25801037

  12. Expression of p53, Bax and Bcl-2 proteins in hepatocytes in non-alcoholic fatty liver disease

    Institute of Scientific and Technical Information of China (English)

    Anatol Panasiuk; Janusz Dzieciol; Bozena Panasiuk; Danuta Prokopowicz

    2006-01-01

    AIM: To analyze the protein expression essential for apoptosis in liver steatosis.METHODS: The expression of proapoptotic proteinsp53, Bax, and antiapoptotic Bcl-2 in hepatocytes with steatosis (SH) and without steatosis (NSH) was evaluated in 84 patients at various stages of non-alcoholic fatty liver disease (NAFLD).RESULTS: Immunohistochemical staining of liver tissue showed the activation of p53 protein in SH and NSH with increased liver steatosis, diminished Bcl-2 and slightly decreased Bax protein. Positive correlation was found between the stage of liver steatosis with p53 expression in SH (r = 0.54, P < 0.01) and NSH (r = 0.49,P < 0.01).The antiapoptotic protein Bcl-2 was diminished together with the advancement of liver steatosis, especially in non-steatosed hepatocytes (r =0.43, P < 001).CONCLUSION: Apoptosis is one of the most important mechanisms leading to hepatocyte elimination in NAFLD. The intensification of inflammation in NAFLD induces proapoptotic protein p53 with the inhibition of antiapoptotic Bcl-2.

  13. Inhibition of Antiapoptotic BCL-XL, BCL-2, and MCL-1 Proteins by Small Molecule Mimetics

    Directory of Open Access Journals (Sweden)

    D.S. Dalafave

    2010-08-01

    Full Text Available Informatics and computational design methods were used to create new molecules that could potentially bind antiapoptotic proteins, thus promoting death of cancer cells. Apoptosis is a cellular process that leads to the death of damaged cells. Its malfunction can cause cancer and poor response to conventional chemotherapy. After being activated by cellular stress signals, proapoptotic proteins bind antiapoptotic proteins, thus allowing apoptosis to go forward. An excess of antiapoptotic proteins can prevent apoptosis. Designed molecules that mimic the roles of proapoptotic proteins can promote the death of cancer cells. The goal of our study was to create new putative mimetics that could simultaneously bind several antiapoptotic proteins. Five new small molecules were designed that formed stable complexes with BCL-2, BCL-XL, and MCL-1 antiapoptotic proteins. These results are novel because, to our knowledge, there are not many, if any, small molecules known to bind all three proteins. Drug-likeness studies performed on the designed molecules, as well as previous experimental and preclinical studies on similar agents, strongly suggest that the designed molecules may indeed be promising drug candidates. All five molecules showed “drug-like” properties and had overall drug-likeness scores between 81% and 96%. A single drug based on these mimetics should cost less and cause fewer side effects than a combination of drugs each aimed at a single protein. Computer-based molecular design promises to accelerate drug research by predicting potential effectiveness of designed molecules prior to laborious experiments and costly preclinical trials.

  14. The distinct role of guanine nucleotide exchange factor Vav1 in Bcl-2 transcription and apoptosis inhibition in Jurkat leukemia T cells

    Institute of Scientific and Technical Information of China (English)

    Jie YIN; Ya-juan WAN; Shi-yang LI; Ming-juan DU; Cui-zhu ZHANG; Xing-long ZHOU; You-jia CAO

    2011-01-01

    Aim: To investigate a novel function of proto-oncogene Vavl in the apoptosis of human leukemia Jurkat cells.Methods: Jurkat cells,Jurkat-derived vavl-null cells(J.Vavl)and Vavl-reconstituted J.WT cells were treated with a Fas agonist antibody,IgM clone CH11.Apoptosis was determined using propidium iodide(PI)staining,Annexin-V staining,DNA fragmentation,cleavage of caspase 3/caspase 8,and poly(ADP-ribose)polymerase(PARP).Mitochondria transmembrane potential(Δψm)was measured using DiOC6(3)staining.Transcription and expression of the Bcl-2 family of proteins were evaluated using semi-quantitative RT-PCR and Western blot,respectively.Bcl-2 promoter activity was analyzed using luciferase reporter assays.Results: Cells lacking Vav1 were more sensitive to Fas-mediated apoptosis than Jurkat and J.WT cells.J.Vav1 cells lost mitochondria transmembrane potential(Δψm)more rapidly upon Fas induction.These phenotypes could be rescued by re-expression of Vav1 in J.Vav1 cells.The expression of Vav1 increased the transcription of pro-survival Bcl-2.The guanine nucleotide exchange activity of Vav1was required for enhancing Bcl-2 promoter activity,and the Vav1 downstream substrate,small GTPase Rac2,was likely involved in the control of Bcl-2 expression.Conclusion: Vav1 protects Jurkat cells from Fas-mediated apoptosis by promoting Bcl-2 transcription through its GEF activity.

  15. Quinacrine induces apoptosis in human leukemia K562 cells via p38 MAPK-elicited BCL2 down-regulation and suppression of ERK/c-Jun-mediated BCL2L1 expression

    Energy Technology Data Exchange (ETDEWEB)

    Changchien, Jung-Jung; Chen, Ying-Jung; Huang, Chia-Hui [Institute of Biomedical Sciences, National Sun Yat-Sen University, Kaohsiung 804, Taiwan (China); Cheng, Tian-Lu [Department of Biomedical Science and Environmental Biology, Kaohsiung Medical University, Kaohsiung 807, Taiwan (China); Lin, Shinne-Ren [Department of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung 807, Taiwan (China); Chang, Long-Sen, E-mail: lschang@mail.nsysu.edu.tw [Institute of Biomedical Sciences, National Sun Yat-Sen University, Kaohsiung 804, Taiwan (China); Department of Biotechnology, Kaohsiung Medical University, Kaohsiung 807, Taiwan (China)

    2015-04-01

    Although previous studies have revealed the anti-cancer activity of quinacrine, its effect on leukemia is not clearly resolved. We sought to explore the cytotoxic effect and mechanism of quinacrine action in human leukemia K562 cells. Quinacrine induced K562 cell apoptosis accompanied with ROS generation, mitochondrial depolarization, and down-regulation of BCL2L1 and BCL2. Upon exposure to quinacrine, ROS-mediated p38 MAPK activation and ERK inactivation were observed in K562 cells. Quinacrine-induced cell death and mitochondrial depolarization were suppressed by the p38MAPK inhibitor SB202190 and constitutively active MEK1 over-expression. Activation of p38 MAPK was shown to promote BCL2 degradation. Further, ERK inactivation suppressed c-Jun-mediated transcriptional expression of BCL2L1. Over-expression of BCL2L1 and BCL2 attenuated quinacrine-evoked mitochondrial depolarization and rescued the viability of quinacrine-treated cells. Taken together, our data indicate that quinacrine-induced K562 cell apoptosis is mediated through mitochondrial alterations triggered by p38 MAPK-mediated BCL2 down-regulation and suppression of ERK/c-Jun-mediated BCL2L1 expression. - Highlights: • Quinacrine induces K562 cell apoptosis via down-regulation of BCL2 and BCL2L1. • Quinacrine induces p38 MAPK activation and ERK inactivation in K562 cells. • Quinacrine elicits p38 MAPK-mediated BCL2 down-regulation. • Quinacrine suppresses ERK/c-Jun-mediated BCL2L1 expression.

  16. Quinacrine induces apoptosis in human leukemia K562 cells via p38 MAPK-elicited BCL2 down-regulation and suppression of ERK/c-Jun-mediated BCL2L1 expression

    International Nuclear Information System (INIS)

    Although previous studies have revealed the anti-cancer activity of quinacrine, its effect on leukemia is not clearly resolved. We sought to explore the cytotoxic effect and mechanism of quinacrine action in human leukemia K562 cells. Quinacrine induced K562 cell apoptosis accompanied with ROS generation, mitochondrial depolarization, and down-regulation of BCL2L1 and BCL2. Upon exposure to quinacrine, ROS-mediated p38 MAPK activation and ERK inactivation were observed in K562 cells. Quinacrine-induced cell death and mitochondrial depolarization were suppressed by the p38MAPK inhibitor SB202190 and constitutively active MEK1 over-expression. Activation of p38 MAPK was shown to promote BCL2 degradation. Further, ERK inactivation suppressed c-Jun-mediated transcriptional expression of BCL2L1. Over-expression of BCL2L1 and BCL2 attenuated quinacrine-evoked mitochondrial depolarization and rescued the viability of quinacrine-treated cells. Taken together, our data indicate that quinacrine-induced K562 cell apoptosis is mediated through mitochondrial alterations triggered by p38 MAPK-mediated BCL2 down-regulation and suppression of ERK/c-Jun-mediated BCL2L1 expression. - Highlights: • Quinacrine induces K562 cell apoptosis via down-regulation of BCL2 and BCL2L1. • Quinacrine induces p38 MAPK activation and ERK inactivation in K562 cells. • Quinacrine elicits p38 MAPK-mediated BCL2 down-regulation. • Quinacrine suppresses ERK/c-Jun-mediated BCL2L1 expression

  17. Depletion of Bcl-2 by an antisense oligonucleotide induces apoptosis accompanied by oxidation and externalization of phosphatidylserine in NCI-H226 lung carcinoma cells.

    Science.gov (United States)

    Koty, Patrick P; Tyurina, Yulia Y; Tyurin, Vladimir A; Li, Shang-Xi; Kagan, Valerian E

    2002-01-01

    Oxidant-induced apoptosis involves oxidation of many different and essential molecules including phospholipids. As a result of this non-specific oxidation, any signaling role of a particular phospholipid-class of molecules is difficult to elucidate. To determine whether preferential oxidation of phosphatidylserine (PS) is an early event in apoptotic signaling related to PS externalization and is independent of direct oxidant exposure, we chose a genetic-based induction of apoptosis. Apoptosis was induced in the lung cancer cell line NCI-H226 by decreasing the amount of Bcl-2 protein expression by preventing the translation of bcl-2 mRNA using an antisense bcl-2 oligonucleotide. Peroxidation of phospholipids was assayed using a fluorescent technique based on metabolic integration of an oxidation-sensitive and fluorescent fatty acid, cis-parinaric acid (PnA), into cellular phospholipids and subsequent HPLC separation of cis-PnA-labeled phospholipids. We found a decrease in Bcl-2 was associated with a selective oxidation of PS in a sub-population of the cells with externalized PS. No significant difference in oxidation of cis-PnA-labeled phospholipids was observed in cells treated with medium alone or a nonsense oligonucleotide. Treatment with either nonsensc or antisense bcl-2 oligonucleotides was not associated with changes in the pattern of individual phospholipid classes as determined by HPTLC. These metabolic and topographical changes in PS arrangement in plasma membrane appear to be early responses to antisense bcl-2 exposure that trigger a PS-dependent apoptotic signaling pathway. This observed externalization of PS may facilitate the 'labeling' of apoptotic cells for recognition by macrophage scavenger receptors and subsequent phagocytic clearance. PMID:12162425

  18. Sheeppox virus SPPV14 encodes a Bcl-2-like cell death inhibitor that counters a distinct set of mammalian proapoptotic proteins.

    Science.gov (United States)

    Okamoto, Toru; Campbell, Stephanie; Mehta, Ninad; Thibault, John; Colman, Peter M; Barry, Michele; Huang, David C S; Kvansakul, Marc

    2012-11-01

    Many viruses express inhibitors of programmed cell death (apoptosis), thereby countering host defenses that would otherwise rapidly clear infected cells. To counter this, viruses such as adenoviruses and herpesviruses express recognizable homologs of the mammalian prosurvival protein Bcl-2. In contrast, the majority of poxviruses lack viral Bcl-2 (vBcl-2) homologs that are readily identified by sequence similarities. One such virus, myxoma virus, which is the causative agent of myxomatosis, expresses a virulence factor that is a potent inhibitor of apoptosis. In spite of the scant sequence similarity to Bcl-2, myxoma virus M11L adopts an almost identical 3-dimensional fold. We used M11L as bait in a sequence similarity search for other Bcl-2-like proteins and identified six putative vBcl-2 proteins from poxviruses. Some are potent inhibitors of apoptosis, in particular sheeppox virus SPPV14, which inhibited cell death induced by multiple agents. Importantly, SPPV14 compensated for the loss of antiapoptotic F1L in vaccinia virus and acts to directly counter the cell death mediators Bax and Bak. SPPV14 also engages a unique subset of the death-promoting BH3-only ligands, including Bim, Puma, Bmf, and Hrk. This suggests that SPPV14 may have been selected for specific biological roles as a virulence factor for sheeppox virus. PMID:22896610

  19. AT-101, a small molecule inhibitor of anti-apoptotic Bcl-2 family members, activates the SAPK/JNK pathway and enhances radiation-induced apoptosis

    Directory of Open Access Journals (Sweden)

    Rooswinkel Rogier

    2009-10-01

    Full Text Available Abstract Background Gossypol, a naturally occurring polyphenolic compound has been identified as a small molecule inhibitor of anti-apoptotic Bcl-2 family proteins. It induces apoptosis in a wide range of tumor cell lines and enhances chemotherapy- and radiation-induced cytotoxicity both in vitro and in vivo. Bcl-2 and related proteins are important inhibitors of apoptosis and frequently overexpressed in human tumors. Increased levels of these proteins confer radio- and chemoresistance and may be associated with poor prognosis. Consequently, inhibition of the anti-apoptotic functions of Bcl-2 family members represents a promising strategy to overcome resistance to anticancer therapies. Methods We tested the effect of (--gossypol, also denominated as AT-101, radiation and the combination of both on apoptosis induction in human leukemic cells, Jurkat T and U937. Because activation of the SAPK/JNK pathway is important for apoptosis induction by many different stress stimuli, and Bcl-XL is known to inhibit activation of SAPK/JNK, we also investigated the role of this signaling cascade in AT-101-induced apoptosis using a pharmacologic and genetic approach. Results AT-101 induced apoptosis in a time- and dose-dependent fashion, with ED50 values of 1.9 and 2.4 μM in Jurkat T and U937 cells, respectively. Isobolographic analysis revealed a synergistic interaction between AT-101 and radiation, which also appeared to be sequence-dependent. Like radiation, AT-101 activated SAPK/JNK which was blocked by the kinase inhibitor SP600125. In cells overexpressing a dominant-negative mutant of c-Jun, AT-101-induced apoptosis was significantly reduced. Conclusion Our data show that AT-101 strongly enhances radiation-induced apoptosis in human leukemic cells and indicate a requirement for the SAPK/JNK pathway in AT-101-induced apoptosis. This type of apoptosis modulation may overcome treatment resistance and lead to the development of new effective combination

  20. AT-101, a small molecule inhibitor of anti-apoptotic Bcl-2 family members, activates the SAPK/JNK pathway and enhances radiation-induced apoptosis

    International Nuclear Information System (INIS)

    Gossypol, a naturally occurring polyphenolic compound has been identified as a small molecule inhibitor of anti-apoptotic Bcl-2 family proteins. It induces apoptosis in a wide range of tumor cell lines and enhances chemotherapy- and radiation-induced cytotoxicity both in vitro and in vivo. Bcl-2 and related proteins are important inhibitors of apoptosis and frequently overexpressed in human tumors. Increased levels of these proteins confer radio- and chemoresistance and may be associated with poor prognosis. Consequently, inhibition of the anti-apoptotic functions of Bcl-2 family members represents a promising strategy to overcome resistance to anticancer therapies. We tested the effect of (-)-gossypol, also denominated as AT-101, radiation and the combination of both on apoptosis induction in human leukemic cells, Jurkat T and U937. Because activation of the SAPK/JNK pathway is important for apoptosis induction by many different stress stimuli, and Bcl-XL is known to inhibit activation of SAPK/JNK, we also investigated the role of this signaling cascade in AT-101-induced apoptosis using a pharmacologic and genetic approach. AT-101 induced apoptosis in a time- and dose-dependent fashion, with ED50 values of 1.9 and 2.4 μM in Jurkat T and U937 cells, respectively. Isobolographic analysis revealed a synergistic interaction between AT-101 and radiation, which also appeared to be sequence-dependent. Like radiation, AT-101 activated SAPK/JNK which was blocked by the kinase inhibitor SP600125. In cells overexpressing a dominant-negative mutant of c-Jun, AT-101-induced apoptosis was significantly reduced. Our data show that AT-101 strongly enhances radiation-induced apoptosis in human leukemic cells and indicate a requirement for the SAPK/JNK pathway in AT-101-induced apoptosis. This type of apoptosis modulation may overcome treatment resistance and lead to the development of new effective combination therapies

  1. The bcl-2, bax gene expression and apoptosis of continuous low-dose-rate irradiation on PC-3 transplanting tumor

    International Nuclear Information System (INIS)

    Objective: The aim of this study was to investigate bcl-2, bax expression and apoptosis of continuous low-dose-rate irradiation on prostate cancer (PC)-3 transplanting tumor. Methods: The expression of bcl-2 and bax associated with apoptosis between experiment and control groups were analyzed using immunohistochemistry at 48, 96 and 192 h after two 125I seed sources implanting model. The correlation between apoptosis and the ratio of bax/bcl-2 was analyzed using Bi-variable linear correlation. SPSS 11.0 was used to analyse the data. Results: The bcl-2 expression in experiment group began to down-regulated significantly after 125I seed irradiation for 48 h as compared with control(t=2.500, P=0.067), though it was not reached to statistical significance. At 96 and 192 h after irradiation, significantly low expression of bcl- 2 were noted (t=4.950, 3.464; P=0.008 and 0.026). In contrast, significantly over expression of bax was noted at 48, 96 and 192 h after 12si irradiation (t=3.334,4.025,5.292;P=0.029, 0.016 and 0.006). The apoptotic index (AI) for PC-3 at 48, 96 and 192 h after 125I irradiation were 22.3%, 21.7% and 30.7%, which was significantly higher than controls when at 96 and 192 h after 125I irradiation (P= 0.016 and 0.036). Moreover, positive correlation was noted between AI and bax/bcl-2 ratio (r=0.784, P= 0.012). Conclusion: Low-dose-rate irradiation could down-regulate the expression of bcl-2, up-regulate the expression of bax and induced PC-3 cells apoptosis. (authors)

  2. RLIP76-dependent suppression of PI3K/AKT/Bcl-2 pathway by miR-101 induces apoptosis in prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jing; Song, Qi; Cai, Yi; Wang, Peng; Wang, Min; Zhang, Dong, E-mail: zhangd1117@yahoo.com

    2015-08-07

    MicroRNA-101 (miR-101) participates in carcinogenesis and tumor progression in various cancers. However, its biological functions in prostate cancer are still unclear. Here, we demonstrate that miR-101 represents a critical role in regulating cell apoptosis in prostate cancer cells. We first demonstrated that miR-101 treatment promoted apoptosis in DU145 and PC3 cells by using flow cytometric analysis and transmission electron microscopy (TEM). To verify the mechanisms, we identified a novel miR-101 target, Ral binding protein 1 (RLIP76). We found miR-101 transfection significantly suppresses RLIP76 expression, which can transactivate phosphorylation of PI3K-Akt signaling, and resulted in an amplification of Bcl2-induced apoptosis. Furthermore, we demonstrated that RLIP76 overexpression could reverse the anti-tumor effects of miR-101 in DU145 and PC3 cells by using flow cytometry assay and MTT assay. Taken together, our results revealed that the effect of miR-101 on prostate cancer cell apoptosis was due to RLIP76 regulation of the PI3K/Akt/Bcl-2 signaling pathway. - Highlights: • miR-101 inhibited prostate cancer cell proliferation and enhanced apoptosis. • miR-101 directly targeted and regulated RLIP76 expression. • miR-101 suppressed PI3K/Akt/Bcl-2 signaling pathway by targeting RLIP76.

  3. RLIP76-dependent suppression of PI3K/AKT/Bcl-2 pathway by miR-101 induces apoptosis in prostate cancer

    International Nuclear Information System (INIS)

    MicroRNA-101 (miR-101) participates in carcinogenesis and tumor progression in various cancers. However, its biological functions in prostate cancer are still unclear. Here, we demonstrate that miR-101 represents a critical role in regulating cell apoptosis in prostate cancer cells. We first demonstrated that miR-101 treatment promoted apoptosis in DU145 and PC3 cells by using flow cytometric analysis and transmission electron microscopy (TEM). To verify the mechanisms, we identified a novel miR-101 target, Ral binding protein 1 (RLIP76). We found miR-101 transfection significantly suppresses RLIP76 expression, which can transactivate phosphorylation of PI3K-Akt signaling, and resulted in an amplification of Bcl2-induced apoptosis. Furthermore, we demonstrated that RLIP76 overexpression could reverse the anti-tumor effects of miR-101 in DU145 and PC3 cells by using flow cytometry assay and MTT assay. Taken together, our results revealed that the effect of miR-101 on prostate cancer cell apoptosis was due to RLIP76 regulation of the PI3K/Akt/Bcl-2 signaling pathway. - Highlights: • miR-101 inhibited prostate cancer cell proliferation and enhanced apoptosis. • miR-101 directly targeted and regulated RLIP76 expression. • miR-101 suppressed PI3K/Akt/Bcl-2 signaling pathway by targeting RLIP76

  4. Increase of bcl-2 Protein Expression in Aggressive Basal Cell Carcinoma of Head and Neck

    OpenAIRE

    Cláudia CAZAL; ELY Mariana Roesch; Ana Paula Veras SOBRAL; Wilton Wilney Nascimento PADILHA

    2006-01-01

    Objective: The aim of this study was to verify the bcl-2 protein expression in 22 cutaneous basal cell carcinomas (BCC) of the head and neck, and to compare it with its aggressive behavior. Method: Tumors were histologically classified in non-aggressive (BCC 1) and aggressive (BCC 2) and then submitted to the immunohistochemistry technique with the streptavidin-biotin peroxidase method using the anti-bcl-2 antibody. Results: After proceeding to morphological analysis, sixteen tumors (72.7%) w...

  5. Adenosine induces cell cycle arrest and apoptosis via cyclinD1/Cdk4 and Bcl-2/Bax pathways in human ovarian cancer cell line OVCAR-3.

    Science.gov (United States)

    Shirali, Saeid; Aghaei, Mahmoud; Shabani, Mahdi; Fathi, Mojtaba; Sohrabi, Majid; Moeinifard, Marzieh

    2013-04-01

    Adenosine is a regulatory molecule with widespread physiological effects in almost every cells and acts as a potent regulator of cell growth. Adenosine has been shown to inhibit cell growth and induce apoptosis in the several cancer cells via caspase activation and Bcl-2/Bax pathway. The present study was designed to understand the mechanism underlying adenosine-induced apoptosis in the OVCAR-3 human ovarian cancer cells. MTT viability, BrdU and cell counting assays were used to study the cell proliferation effect of adenosine in presence of adenosine deaminase inhibitor and the nucleoside transporter inhibitor. Cell cycle analysis, propidium iodide and annexin V staining, caspase-3 activity assay, cyclinD1, Cdk4, Bcl-2 and Bax protein expressions were assessed to detect apoptosis. Adenosine significantly inhibited cell proliferation in a concentration-dependent manner in OVCAR-3 cell line. Adenosine induced cell cycle arrest in G0/G1 phase via Cdk4/cyclinD1-mediated pathway. Adenosine induced apoptosis, which was determined by Annexin V-FITC staining and increased sub-G1 population. Moreover, down-regulation of Bcl-2 protein expression, up-regulation of Bax protein expression and activation of caspase-3 were observed in response to adenosine treatment. The results of this study suggest that extracellular adenosine induced G1 cell cycle arrest and apoptosis in ovarian cancer cells via cyclinD1/ Cdk4 and Bcl-2/Bax pathways and caspase-3 activation. These data might suggest that adenosine could be used as an agent for the treatment of ovarian cancer. PMID:23345014

  6. Melatonin restores normal Bax and Bcl-2 protein expression in the subgranular zone of the dentate gyrus in pinealectomized rats

    Institute of Scientific and Technical Information of China (English)

    Shengchang Zhang; Shuang Zhao; Lu Bai; Mingming Guan; Jielin Mo; Ling Lan

    2011-01-01

    In this study, we sought to elucidate the effects of melatonin on learning and memory as well as apoptosis and expression of the Bax or Bcl-2 proteins in the subgranular zone of the dentate gyrus in pinealectomized rats. Using the Morris water maze and the olfactory memory tests, we found that the average escape latency in pinealectomized rats was clearly increased compared with sham-operated rats. Moreover, the average escape latency in the melatonin-treated and pinealectomized rats was longer than that in the sham-operated rats and shorter than that in the pinealectomized and untreated rats. Immunohistochemistry and terminal-deoxynucleoitidyl transferase mediated nick end labeling (TUNEL) showed that there were fewer Bax immunoreactive cells and TUNEL-positive (apoptotic) cells but more Bcl-2 immunoreactive cells in the melatonin-treated rats compared with the pinealectomized rats. The sham-operated rats showed numbers of these cells similar to the melatonin-treated rats. These experimental findings demonstrate that melatonin treatment may reduce abnormal apoptosis by promoting gene expression of Bax and suppressing gene expression of Bcl-2 in the subgranular zone of the dentate gyrus in pinealectomized rats. These effects appear to result in the inhibition of cellular apoptosis and the improvement of spatial learning and memory in pinealectomized rats.

  7. Correlation between expression of Bcl-2 protein and cell apoptosis in functioning and non-functioning adrenal tumours%功能性和非功能性肾上腺肿瘤与Bcl-2蛋白表达和细胞凋亡的关系

    Institute of Scientific and Technical Information of China (English)

    杨勇; 徐祗顺; 殷刚

    2006-01-01

    目的 探讨功能性和非功能性肾上腺肿瘤组织中Bcl-2的表达水平和细胞凋亡的关系.方法 运用免疫组织化学染色和TUNEL法检测细胞凋亡情况,探讨4例正常肾上腺(NA)、33例有功能性肾上腺肿瘤(FAT)和23例非功能性肾上腺肿瘤(NFAT)的Bcl-2表达及细胞凋亡情况.结果 Bcl-2阳性细胞的平均百分数在NA、FAT、NFAT分别为(3.8±1.1)%、(6.3±1.2)%、(13.1±1.8)%,其中FAT与NFAT、NA与NFAT比较,均有显著性差异(P<0.05);FAT与NA比较无显著性差异(P>0.05).凋亡的阳性细胞率FAT(1.14±0.30)%高于NFAT的(0.48±0.25)%和NA(0.18±0.05)%,其中FAT与NFAT、FAT与NA、NFAT与NA比较均有显著性差异(P<0.05).Bcl-2的表达与细胞凋亡指数(AI)呈显著负相关(rs=-0.560,P<0.02;rs=-0.530,P<0.03).结论 Bcl-2表达与细胞凋亡抑制关系密切;Bcl-2的表达及细胞凋亡检测对功能性肾上腺肿瘤和非功能性肾上腺肿瘤有一定诊断意义.

  8. Targeting Antiapoptotic Bcl-2 Family Members with Cell-Permeable BH3 Peptides Induces Apoptosis Signaling, Death in Head, Neck Squamous Cell Carcinoma Cells

    Directory of Open Access Journals (Sweden)

    Rongxiu Li

    2007-10-01

    Full Text Available Head, neck squamous cell carcinomas (HNSCCs are frequently characterized by chemotherapy, radiation resistance, by overexpression of Bcl-XL, an antiapoptotic member of the Bcl-2 protein family. In this report, we examined whether cell-permeable peptides derived from the BH3 domains of proapoptotic Bax, Bad, or Bak could be used to target Bcl-XL and/or Bcl-2 in HNSCC cells, induce apoptotic death in these cells. To render the peptides cell-permeable, Antennapedia (Ant or polyarginine (R8 peptide transduction domain was fused to the amino termini. Fluorescence microscopy of peptide-treated HNSCC cells revealed that the BH3 peptides colocalized with mitochondria, the site of Bcl-XL, Bcl-2 expression. By contrast, a mutant peptide (BaxE BH3 that cannot bind Bcl-XL or Bcl-2 was diffusely localized throughout the cytoplasm. Treatment of three HNSCC cell lines (1483, UM-22A, UM-22B with the wild-type BH3 peptides resulted in loss of viability, induction of apoptosis, as assessed by 3-(4,5-dimethythiazol-2yl-5-(3-carboxymethoxyphenyl-2-(4-sulfophenyl-2H-tetrazolium (MTS assays, annexin V staining. In general, Ant-conjugated peptides were more potent than R8-conjugated peptides, Bad BH3 peptide was typically more potent than Bax BH3 or Bak BH3. Treatment of purified HNSCC mitochondria with BH3 peptides resulted in robust release of cytochrome c. Thus, the relative apoptosis resistance of HNSCC cells is not due to a deficit in this step of the intrinsic, mitochondrialmediated apoptosis pathway. We conclude that cellpermeable BH3 peptides can be used to target Bcl-XL and/or Bcl-2 in HNSCC, that targeting of these proteins may have therapeutic value in the treatment of this disease.

  9. Oridonin induces apoptosis of HeLa cells via altering expres sion of Bcl-2/Bax and activating caspase-3/ICAD pathway

    Institute of Scientific and Technical Information of China (English)

    Chun-ling ZHANG; Li-jun WU; Shin-ichi TASHIRO; Satoshi ONODERA; Takashi IKEJIMA

    2004-01-01

    AIM: To study the mechanisms by which oridonin inhibited HeLa cell growth in vitro. METHODS: Viability of oridonin-induced HeLa cells was measured by MTT assay. Apoptotic cells with condensed nuclei were visualized by phase contrast microscopy. Nucleosomal DNA fragmentation was assayed by agarose gel electrophoresis.Caspase activity was assayed using fiuorometric protease assay. ICAD, Bcl-2, and Bax proteins expression were detected by Western blot analysis. RESULTS: Oridonin induced oligonucleosomal fragmentation of DNA and increased caspase-3 activity, on the other hand, reduced the expression of inhibitor of caspase-3-activated DNase (ICAD), a caspase-3 substrate, at 12 h in HeLa cells. Oridonin-induced DNA fragmentation, caspase-3 activation and down-regulation of ICAD expression were effectively inhibited by a caspase-3 inhibitor, z-DEVD-fmk (z-AspGlu-Val-Asp-fmk). However, pretreatment with an inhibitor of poly (ADP-ribose) polymerase (PARP), 3, 4-dihydro5-[4-(1-piperidinyl)butoxy]-1 (2H)-isoquinolinone (DPQ), did not suppress oridonin-induced HeLa cell death. In addition, oridonin-induced apoptosis was associated with an increase in the expression of the apoptosis inducer Bax, and a significant reduction in expression of the apoptosis suppressor Bcl-2 in mitochondria. CONCLUSION:Oridonin induces HeLa cells apoptosis by altering balance of Bcl-2 and Bax protein expression and activation of caspase-3/ICAD pathway.

  10. Removal of the BH4 Domain from Bcl-2 Protein Triggers an Autophagic Process that Impairs Tumor Growth12

    Science.gov (United States)

    Trisciuoglio, Daniela; De Luca, Teresa; Desideri, Marianna; Passeri, Daniela; Gabellini, Chiara; Scarpino, Stefania; Liang, Chengyu; Orlandi, Augusto; Del Bufalo, Donatella

    2013-01-01

    Here, we show that forced expression of a B-cell lymphoma 2 (bcl-2) protein lacking residues 1 to 36 at the N-terminal, including the entire Bcl-2 homology 4 (BH4) domain, determines reduction of in vitro and in vivo human melanoma growth. Noteworthy, melanoma cells in vivo exhibit markedly increased autophagy, as response to expression of bcl-2 protein deleted of its BH4 domain. This observation led to the identification of a novel gain of function for bcl-2 protein lacking the BH4 domain. In particular, upon different autophagic stimuli in vitro, overexpression of bcl-2 protein deleted of BH4 domain induces autophagosome accumulation, conversion of microtubule-associated protein 1 light chain 3B-II, reduced expression of p62/SQSTM1 protein, and thereby enhanced autophagic flux. The relevance of Beclin-1 is evidenced by the fact that 1) the autophagy-promoting and growth-inhibiting properties are partially rescued by Beclin-1 knockdown in cells expressing bcl-2 protein lacking the BH4 domain, 2) Beclin-1 only interacts with wild-type but not with deleted bcl-2, and 3) BH4 domain removal from bcl-2 protein does not influence in vitro and in vivo growth of tumor cells expressing low levels of endogenous Beclin-1. These results provide new insight into molecular mechanism of bcl-2 functions and represent a rationale for the development of agents interfering with the BH4 domain of bcl-2 protein. PMID:23479509

  11. Removal of the BH4 Domain from Bcl-2 Protein Triggers an Autophagic Process that Impairs Tumor Growth

    Directory of Open Access Journals (Sweden)

    Daniela Trisciuoglio

    2013-03-01

    Full Text Available Here, we show that forced expression of a B-cell lymphoma 2 (bcl-2 protein lacking residues 1 to 36 at the N-terminal, including the entire Bcl-2 homology 4 (BH4 domain, determines reduction of in vitro and in vivo human melanoma growth. Noteworthy, melanoma cells in vivo exhibit markedly increased autophagy, as response to expression of bcl-2 protein deleted of its BH4 domain. This observation led to the identification of a novel gain of function for bcl-2 protein lacking the BH4 domain. In particular, upon different autophagic stimuli in vitro, overexpression of bcl-2 protein deleted of BH4 domain induces autophagosome accumulation, conversion of microtubule-associated protein 1 light chain 3B-II, reduced expression of p62/SQSTM1 protein, and thereby enhanced autophagic flux. The relevance of Beclin-1 is evidenced by the fact that 1 the autophagy-promoting and growth-inhibiting properties are partially rescued by Beclin-1 knockdown in cells expressing bcl-2 protein lacking the BH4 domain, 2 Beclin-1 only interacts with wild-type but not with deleted bcl-2, and 3 BH4 domain removal from bcl-2 protein does not influence in vitro and in vivo growth of tumor cells expressing low levels of endogenous Beclin-1. These results provide new insight into molecular mechanism of bcl-2 functions and represent a rationale for the development of agents interfering with the BH4 domain of bcl-2 protein.

  12. Removal of the BH4 domain from Bcl-2 protein triggers an autophagic process that impairs tumor growth.

    Science.gov (United States)

    Trisciuoglio, Daniela; De Luca, Teresa; Desideri, Marianna; Passeri, Daniela; Gabellini, Chiara; Scarpino, Stefania; Liang, Chengyu; Orlandi, Augusto; Del Bufalo, Donatella

    2013-03-01

    Here, we show that forced expression of a B-cell lymphoma 2 (bcl-2) protein lacking residues 1 to 36 at the N-terminal, including the entire Bcl-2 homology 4 (BH4) domain, determines reduction of in vitro and in vivo human melanoma growth. Noteworthy, melanoma cells in vivo exhibit markedly increased autophagy, as response to expression of bcl-2 protein deleted of its BH4 domain. This observation led to the identification of a novel gain of function for bcl-2 protein lacking the BH4 domain. In particular, upon different autophagic stimuli in vitro, overexpression of bcl-2 protein deleted of BH4 domain induces autophagosome accumulation, conversion of microtubule-associated protein 1 light chain 3B-II, reduced expression of p62/SQSTM1 protein, and thereby enhanced autophagic flux. The relevance of Beclin-1 is evidenced by the fact that 1) the autophagy-promoting and growth-inhibiting properties are partially rescued by Beclin-1 knockdown in cells expressing bcl-2 protein lacking the BH4 domain, 2) Beclin-1 only interacts with wild-type but not with deleted bcl-2, and 3) BH4 domain removal from bcl-2 protein does not influence in vitro and in vivo growth of tumor cells expressing low levels of endogenous Beclin-1. These results provide new insight into molecular mechanism of bcl-2 functions and represent a rationale for the development of agents interfering with the BH4 domain of bcl-2 protein. PMID:23479509

  13. Increase of bcl-2 Protein Expression in Aggressive Basal Cell Carcinoma of Head and Neck

    Directory of Open Access Journals (Sweden)

    Cláudia CAZAL

    2006-09-01

    Full Text Available Objective: The aim of this study was to verify the bcl-2 protein expression in 22 cutaneous basal cell carcinomas (BCC of the head and neck, and to compare it with its aggressive behavior. Method: Tumors were histologically classified in non-aggressive (BCC 1 and aggressive (BCC 2 and then submitted to the immunohistochemistry technique with the streptavidin-biotin peroxidase method using the anti-bcl-2 antibody. Results: After proceeding to morphological analysis, sixteen tumors (72.7% were considered aggressive and six (27.3% non-aggressive. Immunohistochemistry analysis showed that thirteen (59.1% lesions were positive staining and nine (40.9% were negative to the bcl-2 protein. Considering the positive lesions, 12 (92.3% were aggressive and one (7.7% non-aggressive. The relation between bcl-2 protein staining and the tumor aggressiveness was statistically significant (p<0.05 - Fisher's exact Test. Conclusion: The results suggest a relationship between the bcl-2 protein expression and the histological aggressiveness grade in the BCC of the head and neck group studied may exist.

  14. Expression of P53, P21/WAF/CIP, BCL-2, BAX, BCL-X, and BAK in radiation-induced apoptosis in testicular germ cell tumor lines

    International Nuclear Information System (INIS)

    Purpose: Testicular germ cell tumors (TGCTs) represent one of the few tumor types that are curable by antineoplastic therapy, probably due to the high sensitivity of this neoplasm to induction of apoptosis by chemotherapeutic agents and/or ionizing radiation. Here, we tested cell susceptibility to radiation-induced apoptosis in a panel of TGCT cell lines and attempted to correlate this with the known potentially relevant molecular determinants (p53 gene status and Bcl-2 family proteins) of apoptosis. Methods and Materials: Induction of apoptosis by γ-radiation was morphologically recognized in NT2, NCCIT, S2, and 2102 EP using Hoechst/PI staining and additionally confirmed by Western blot analysis of PARP cleavage. The p53 gene status was estimated by sequence analysis. Expression of p21/WAF/CIP was determined by Northern blot analysis and immunoblotting was used to monitor p53, Bax, Bcl-2, Bcl-x, and Bak protein levels. In vitro colony formation was studied to establish clonogenic survival curves. Results: NT2 and NCCIT appeared to be susceptible for radiation-induced apoptosis, contrasting 2102 EP and S2 which were highly resistant. Sequence analysis showed that NT2, S2, and 2102 EP are homozygous for wild-type p53 (wtp53), whereas NCCIT contains mutant p53 (mtp53). NT2 and 2102 EP cells showed radiation-induced p53 upregulation, while NCCIT (mtp53) and S2 (no p53 protein) cells did not. Consistently, γ-radiation-induced DNA damage resulted in a p53-dependent transactivation of the p21/WAF/CIP gene in NT2 and 2102 EP, but not in mtp53-containing NCCIT cells and p53 nonexpressing S2 cells. Constitutive expression of Bax, Bcl-2, Bcl-x, and Bak was not affected by radiation and showed no correlation with cell susceptibility to radiation-induced apoptosis. A discrepancy was found between apoptosis and reproductive death. Conclusions: The present study revealed that: i) the presence of wtp53 may not be absolutely required for the hypersensitivity for radiation

  15. Structural and biochemical analysis of Bcl-2 interaction with the hepatitis B virus protein HBx.

    Science.gov (United States)

    Jiang, Tianyu; Liu, Minhao; Wu, Jianping; Shi, Yigong

    2016-02-23

    HBx is a hepatitis B virus protein that is required for viral infectivity and replication. Anti-apoptotic Bcl-2 family members are thought to be among the important host targets of HBx. However, the structure and function of HBx are poorly understood and the molecular mechanism of HBx-induced carcinogenesis remains unknown. In this study, we report biochemical and structural characterization of HBx. The recombinant HBx protein contains metal ions, in particular iron and zinc. A BH3-like motif in HBx (residues 110-135) binds Bcl-2 with a dissociation constant of ∼193 μM, which is drastically lower than that for a canonical BH3 motif from Bim or Bad. Structural analysis reveals that, similar to other BH3 motifs, the BH3-like motif of HBx adopts an amphipathic α-helix and binds the conserved BH3-binding groove on Bcl-2. Unlike the helical Bim or Bad BH3 motif, the C-terminal portion of the bound HBx BH3-like motif has an extended conformation and makes considerably fewer interactions with Bcl-2. These observations suggest that HBx may modulate Bcl-2 function in a way that is different from that of the classical BH3-only proteins. PMID:26858413

  16. Apoptosis and the BCL-2 gene family - patterns of expression and prognostic value in STAGE I and II follicular center lymphoma

    International Nuclear Information System (INIS)

    Purpose: The prognostic significance of spontaneous levels of apoptosis and Bcl-2, Bax, and Bcl-x protein expression in follicular center lymphoma (FCL) is unknown. The objectives of this retrospective study were (1) to investigate the relationship between pretreatment apoptosis levels and long-term treatment outcome in patients with Stage I and II FCL; (2) to define the incidence and patterns of Bax and Bcl-x protein expression in human FC; and (3) to determine the relationship of Bcl-2, Bax, and Bcl-x expression with spontaneous apoptosis levels and clinical outcome in localized FCL. Methods and Materials: Between 1974 and 1988, 144 patients with Stage I or II FCL were treated. Hematoxylin and eosin (H and E) stained tissue sections of pretreatment specimens were retrieved for 96 patients. Treatment consisted of regional radiation therapy (XRT) for 25 patients, combined modality therapy (CMT) consisting of combination chemotherapy and XRT for 57 patients, and other treatments for 14 patients. Median follow-up for living patients was nearly 12 years. The apoptotic index (AI) was calculated by dividing the number of apoptotic cells by the total number of cells counted and multiplying by 100. Expression of Bcl-2, Bax, and Bcl-x proteins was assessed using immunohistochemistry. Results: The mean and median AI values for the entire group were 0.53 and 0.4, respectively (range: 0-5.2). The AI strongly correlated with cytologic grade, with mean AI values of 0.25 for grade 1, 0.56 for grade 2, and 0.84 for grade 3 (p < 0.0005; Kendall correlation). A positive correlation was present between grouped AI and grouped mitotic index (MI) (p = 0.014). For patients treated with CMT, an AI < 0.4 correlated with improved freedom from relapse (FFR) (p = 0.0145) and overall survival (OS) (p = 0.0081). An AI < 0.4 did not correlate with clinical outcome for the entire cohort or for patients receiving XRT only. Staining of tumor follicles for the Bcl-2 protein was positive, variable

  17. MicroRNA-744 inhibited cervical cancer growth and progression through apoptosis induction by regulating Bcl-2.

    Science.gov (United States)

    Chen, Xiao-Fang; Liu, Yun

    2016-07-01

    Growing evidence suggests that microRNA plays an essential role in the development and metastasis of many tumor progressions, including cervical cancer. Aberrant miR-744 expression has been indicated in many growth of tumor, the mechanism of miR-744 inhibits both the proliferation and metastatic ability for cervical cancer remains unclear. Accumulating evidences reported that Bcl-2 signal pathway plays an important role in the cellular process, such as apoptosis, cell growth and proliferation. The goal of this study was to identify miR-744 that could inhibit the growth, migration, invasion, proliferation and metastasis of gastric cancer through targeting Bcl-2 expression. Real-time PCR (RT-qPCR) was used to quantify miR-744 expression in vitro and vivo experiments. The biological functions of miR-744 were determined via cell proliferation. Our study indicated that miR-744 targeted on Bcl-2, which leads to the inactivation of apoptosis signaling and the cell proliferation of cervical cancer cells, ameliorating cervical cancer growth and progression. In addition, both up-regulation of miR-744 and down-regulation of Bcl-2 could stimulate Caspase-3 expression, promoting apoptosis of cervical cancer cells. Therefore, our research revealed the mechanistic links between miR-744 and Bcl-2 in the pathogenesis of cervical cancer through modulation of Caspase-3, leading to the inhibition of cervical cancer cell growth. And targeting miR-744 could be served as a novel strategy for future cervical cancer therapy clinically. PMID:27261616

  18. Dexamethasone protected human glioblastoma U87MG cells from temozolomide induced apoptosis by maintaining Bax:Bcl-2 ratio and preventing proteolytic activities

    Directory of Open Access Journals (Sweden)

    Patel Sunil J

    2004-12-01

    Full Text Available Abstract Background Glioblastoma is the deadliest and most prevalent brain tumor. Dexamethasone (DXM is a commonly used steroid for treating glioblastoma patients for alleviation of vasogenic edema and pain prior to treatment with chemotherapeutic drugs. Temozolomide (TMZ, an alkylating agent, has recently been introduced in clinical trials for treating glioblastoma. Here, we evaluated the modulatory effect of DXM on TMZ induced apoptosis in human glioblastoma U87MG cells. Results Freshly grown cells were treated with different doses of DXM or TMZ for 6 h followed by incubation in a drug-free medium for 48 h. Wright staining and ApopTag assay showed no apoptosis in cells treated with 40 μM DXM but considerable amounts of apoptosis in cells treated with 100 μM TMZ. Apoptosis in TMZ treated cells was associated with an increase in intracellular free [Ca2+], as determined by fura-2 assay. Western blot analyses showed alternations in the levels of Bax (pro-apoptotic and Bcl-2 (anti-apoptotic proteins resulting in increased Bax:Bcl-2 ratio in TMZ treated cells. Western blot analyses also detected overexpression of calpain and caspase-3, which cleaved 270 kD α-spectrin at specific sites for generation of 145 and 120 kD spectrin break down products (SBDPs, respectively. However, 1-h pretreatment of cells with 40 μM DXM dramatically decreased TMZ induced apoptosis, decreasing Bax:Bcl-2 ratio and SBDPs. Conclusion Our results revealed an antagonistic effect of DXM on TMZ induced apoptosis in human glioblastoma U87MG cells, implying that treatment of glioblastoma patients with DXM prior to chemotherapy with TMZ might result in an undesirable clinical outcome.

  19. Removal of the BH4 Domain from Bcl-2 Protein Triggers an Autophagic Process that Impairs Tumor Growth12

    OpenAIRE

    Trisciuoglio, Daniela; De Luca, Teresa; Desideri, Marianna; Passeri, Daniela; Gabellini, Chiara; Scarpino, Stefania; Liang, Chengyu; Orlandi, Augusto; Del Bufalo, Donatella

    2013-01-01

    Here, we show that forced expression of a B-cell lymphoma 2 (bcl-2) protein lacking residues 1 to 36 at the N-terminal, including the entire Bcl-2 homology 4 (BH4) domain, determines reduction of in vitro and in vivo human melanoma growth. Noteworthy, melanoma cells in vivo exhibit markedly increased autophagy, as response to expression of bcl-2 protein deleted of its BH4 domain. This observation led to the identification of a novel gain of function for bcl-2 protein lacking the BH4 domain. I...

  20. Roscovitine-induced apoptosis in neutrophils and neutrophil progenitors is regulated by the Bcl-2-family members Bim, Puma, Noxa and Mcl-1.

    Directory of Open Access Journals (Sweden)

    Sanjivan Gautam

    Full Text Available Neutrophil granulocyte (neutrophil apoptosis plays a key role in determining inflammation in infectious and non-infectious settings. Recent work has shown that inhibitors of cyclin-dependent kinases (cdk such as roscovitine can potently induce neutrophil apoptosis and reduce inflammation. Using a conditional Hoxb8-expression system we tested the participation of Bcl-2-family proteins to roscovitine-induced apoptosis in mouse neutrophils and in neutrophil progenitor cells. Bcl-2 strongly protected against roscovitine-induced apoptosis in neutrophils. The isolated loss of either Bim or noxa provided significant, partial protection while protection through combined loss of Bim and noxa or Bim and Puma was only slightly greater than this individual loss. The only substantial change in protein levels observed was the loss of Mcl-1, which was not transcriptional and was inhibited by proteasome blockade. In progenitor cells there was no protection by the loss of Bim alone but substantial protection by the loss of both Bim and Puma; surprisingly, strongest protection was seen by the isolated loss of noxa. The pattern of protein expression and Mcl-1-regulation in progenitor cells was very similar to the one observed in differentiated neutrophils. In addition, roscovitine strongly inhibited proliferation in progenitor cells, associated with an accumulation of cells in G2/M-phase.

  1. Nitric oxide and oxygen radicals induced apoptosis via bcl-2 and p53 pathway in hypoxia-reoxygenated cardiomyocytes

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Neonatal rat cardiomyocytes were subjected to 24 h of hypoxia 95%N2/5%CO2 and 24 h of hypoxia plus 4 h of reoxygenation 95%O2/5%CO2. 24 h of hypoxia increased the levels of NO, TBARS and LDH. 24 h of hypoxia plus 4 h of reoxygenation decreased the levels of NO, but further increased TBARS and LDH. The hypoxia up-regulated the expression of bcl-2, p53 and p21/waf1/cip1 but the reoxygenation down-regulated the expression of bcl-2, and further up-regulated p53 and p21/waf1/cip1. The hypoxia increased cell apoptosis and reoxygenation further increased both apoptotic and necrotic cell death. NO, TBARS, DNA fragmentation and cell apoptosis were enhanced by SNP and inhibited by L-NAME respectively. In addition, SOD/catalase down-regulated the expression of p53, p21/wafl/cipl and TBARS but up-regulated bcl-2 and increased indirectly the level of NO, and inhibited DNA fragmentation. The results suggest that hypoxia-induced cell death is associated with the activation of NO, bcl-2 and p53 pathway, while hypoxia-reoxygenation induced cell death via the generation of reactive oxygen species and activation of p53 pathway. The present study clarified that NO may be an initiative signal to apoptotic cell death and the activation of bcl-2, p53 and p21/waf1/cip1 pathway in hypoxic and hypoxia-reoxygenated cardiomyocytes.

  2. Mutual regulation of Bcl-2 proteins independent of the BH3 domain as shown by the BH3-lacking protein Bcl-x(AK.

    Directory of Open Access Journals (Sweden)

    Michael Plötz

    Full Text Available The BH3 domain of Bcl-2 proteins was regarded as indispensable for apoptosis induction and for mutual regulation of family members. We recently described Bcl-x(AK, a proapoptotic splice product of the bcl-x gene, which lacks BH3 but encloses BH2, BH4 and a transmembrane domain. It remained however unclear, how Bcl-x(AK may trigger apoptosis.For efficient overexpression, Bcl-x(AK was subcloned in an adenoviral vector under Tet-OFF control. The construct resulted in significant apoptosis induction in melanoma and nonmelanoma cell lines with up to 50% apoptotic cells as well as decreased cell proliferation and survival. Disruption of mitochondrial membrane potential, and cytochrome c release clearly indicated activation of the mitochondrial apoptosis pathways. Both Bax and Bak were activated as shown by clustering and conformation analysis. Mitochondrial translocation of Bcl-x(AK appeared as an essential and initial step. Bcl-x(AK was critically dependent on either Bax or Bak, and apoptosis was abrogated in Bax/Bak double knockout conditions as well by overexpression of Bcl-2 or Bcl-x(L. A direct interaction with Bcl-2, Bax, Bad, Noxa or Puma was however not seen by immunoprecipitation. Thus besides BH3-mediated interactions, there exists an additional way for mutual regulation of Bcl-2 proteins, which is independent of the BH3. This pathway appears to play a supplementary role also for other proapoptotic family members, and its unraveling may help to overcome therapy resistance in cancer.

  3. Small Molecule Inhibitors of Bcl-2 Family Proteins for Pancreatic Cancer Therapy

    International Nuclear Information System (INIS)

    Pancreatic cancer (PC) has a complex etiology and displays a wide range of cellular escape pathways that allow it to resist different treatment modalities. Crucial signaling molecules that function downstream of the survival pathways, particularly at points where several of these pathways crosstalk, provide valuable targets for the development of novel anti-cancer drugs. Bcl-2 family member proteins are anti-apoptotic molecules that are known to be overexpressed in most cancers including PC. The anti-apoptotic machinery has been linked to the observed resistance developed to chemotherapy and radiation and therefore is important from the targeted drug development point of view. Over the past ten years, our group has extensively studied a series of small molecule inhibitors of Bcl-2 against PC and provide solid preclinical platform for testing such novel drugs in the clinic. This review examines the efficacy, potency, and function of several small molecule inhibitor drugs targeted to the Bcl-2 family of proteins and their preclinical progress against PC. This article further focuses on compounds that have been studied the most and also discusses the anti-cancer potential of newer class of Bcl-2 drugs

  4. Inhibition of Bcl-2 or IAP proteins does not provoke mutations in surviving cells

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Mutagenicities of anti-cancer drugs were tested using HPRT, γH2AX and comet assays. • TRAIL, doxorubicin and etoposide were more mutagenic than BH3- or Smac-mimetics. • Physiologically achievable levels of the BH3-mimetic ABT-737 were not mutagenic. • High concentrations of ABT-737 provoked mutations via an off-target mechanism. • Even very high concentrations of IAP antagonists were not mutagenic. - Abstract: Chemotherapy and radiotherapy can cause permanent damage to the genomes of surviving cells, provoking severe side effects such as second malignancies in some cancer survivors. Drugs that mimic the activity of death ligands, or antagonise pro-survival proteins of the Bcl-2 or IAP families have yielded encouraging results in animal experiments and early phase clinical trials. Because these agents directly engage apoptosis pathways, rather than damaging DNA to indirectly provoke tumour cell death, we reasoned that they may offer another important advantage over conventional therapies: minimisation or elimination of side effects such as second cancers that result from mutation of surviving normal cells. Disappointingly, however, we previously found that concentrations of death receptor agonists like TRAIL that would be present in vivo in clinical settings provoked DNA damage in surviving cells. In this study, we used cell line model systems to investigate the mutagenic capacity of drugs from two other classes of direct apoptosis-inducing agents: the BH3-mimetic ABT-737 and the IAP antagonists LCL161 and AT-406. Encouragingly, our data suggest that IAP antagonists possess negligible genotoxic activity. Doses of ABT-737 that were required to damage DNA stimulated Bax/Bak-independent signalling and exceeded concentrations detected in the plasma of animals treated with this drug. These findings provide hope that cancer patients treated by BH3-mimetics or IAP antagonists may avoid mutation-related illnesses that afflict

  5. Inhibition of Bcl-2 or IAP proteins does not provoke mutations in surviving cells

    Energy Technology Data Exchange (ETDEWEB)

    Shekhar, Tanmay M. [Department of Biochemistry, La Trobe Institute for Molecular Science, La Trobe University, Bundoora 3083 (Australia); Green, Maja M. [Department of Biochemistry, La Trobe Institute for Molecular Science, La Trobe University, Bundoora 3083 (Australia); Department of Anatomy & Neuroscience, The University of Melbourne, Parkville 3010 (Australia); Rayner, David M.; Miles, Mark A.; Cutts, Suzanne M. [Department of Biochemistry, La Trobe Institute for Molecular Science, La Trobe University, Bundoora 3083 (Australia); Hawkins, Christine J., E-mail: c.hawkins@latrobe.edu.au [Department of Biochemistry, La Trobe Institute for Molecular Science, La Trobe University, Bundoora 3083 (Australia)

    2015-07-15

    Graphical abstract: - Highlights: • Mutagenicities of anti-cancer drugs were tested using HPRT, γH2AX and comet assays. • TRAIL, doxorubicin and etoposide were more mutagenic than BH3- or Smac-mimetics. • Physiologically achievable levels of the BH3-mimetic ABT-737 were not mutagenic. • High concentrations of ABT-737 provoked mutations via an off-target mechanism. • Even very high concentrations of IAP antagonists were not mutagenic. - Abstract: Chemotherapy and radiotherapy can cause permanent damage to the genomes of surviving cells, provoking severe side effects such as second malignancies in some cancer survivors. Drugs that mimic the activity of death ligands, or antagonise pro-survival proteins of the Bcl-2 or IAP families have yielded encouraging results in animal experiments and early phase clinical trials. Because these agents directly engage apoptosis pathways, rather than damaging DNA to indirectly provoke tumour cell death, we reasoned that they may offer another important advantage over conventional therapies: minimisation or elimination of side effects such as second cancers that result from mutation of surviving normal cells. Disappointingly, however, we previously found that concentrations of death receptor agonists like TRAIL that would be present in vivo in clinical settings provoked DNA damage in surviving cells. In this study, we used cell line model systems to investigate the mutagenic capacity of drugs from two other classes of direct apoptosis-inducing agents: the BH3-mimetic ABT-737 and the IAP antagonists LCL161 and AT-406. Encouragingly, our data suggest that IAP antagonists possess negligible genotoxic activity. Doses of ABT-737 that were required to damage DNA stimulated Bax/Bak-independent signalling and exceeded concentrations detected in the plasma of animals treated with this drug. These findings provide hope that cancer patients treated by BH3-mimetics or IAP antagonists may avoid mutation-related illnesses that afflict

  6. Study of the expressions of p53 and bcl-2 genes, the telomerase activity and apoptosis in GIST patients

    Institute of Scientific and Technical Information of China (English)

    Qiang Wang; You-Wei Kou

    2007-01-01

    AIM: To explore the relationship between clinicobiological behavior and the expression levels of telomerase activity,apoptosis, p53 gene and bcl-2 gene in gastrointestinal stromal tumors (GISTs).METHODS: The intensity of telomerase activity,apoptosis, p53 and bcl-2 expression in GISTs were detected by telomeric repeat amplification protocol, in situ end-labeling technique, and immunohistochemistry,respectively.RESULTS: The positive rates of telomerase activity of malignant GIST, potential malignant GIST and benign GIST were 85% (17/20), 22.8% (2/9) and 0 (0/9),respectively. The apoptosis indices of malignant GIST,potential malignant GIST, and benign GIST were 11.7 ± 5.4, 30.2 ± 5.6 and 45.2 ± 7.2, respectively. The intensity of telomerase activity and apoptosis were related to the biological characteristics of GISTs (85% vs 22.8%, 0, 0; P < 0.01 or 11.7±5.4 vs 30.2 ± 5.6, 45.2 ± 7.2, 72.1 ± 9.3; P < 0.05). The intensity of telomerase activity was negatively correlated with cellular apoptosis (22.9 ± 8.4 vs 9.5 ± 5.7, P < 0.01). The intensity of telomerase activity was positively correlated with p53,bcl-2 expression (40.0% vs 78.9%, 40.0% vs 84.2%;P < 0.05).CONCLUSION: The detection of telomerase activity,apoptosis and its control genes in GIST will be helpful for the discrimination of the malignant and benign GIST and evaluation of the prognosis.

  7. Assessment of expression of selected Bcl-2 family proteins in lymphoid infiltration in patients with B-cell chronic lymphocytic leukaemia treated with nucleoside analogues.

    Directory of Open Access Journals (Sweden)

    Janusz Kłoczko

    2008-12-01

    Full Text Available B-cell chronic lymphocytic leukaemia (B-CLL is characterized by clonal growth and accumulation of mature lymphoid cells due to disturbance in genetically regulated form of cell death called apoptosis. The intrinsic mechanism of apoptosis is controlled by Bcl-2 family proteins. Purine nucleoside analogues induce the apoptosis in cells in a state of quiescence. The aim of the study was to assess expression of selected Bcl-2 family proteins in neoplastic infiltration in bone marrow in patients with B-CLL treated with nucleoside analogues. The study comprised examination of bone marrow obtained routinely by trephine biopsy from 18 patients with B-CLL diagnosed before administration of purine nucleoside analogues treatment and after its completion. Expression of Bcl-2, Bcl-x and Bax proteins was examined. Lymphoid cells in bone marrow were present in all patients before administration of treatment. After treatment in two patients bone marrow was infiltrated in diffuse pattern, whereas other patients presented nodular pattern of infiltration. The difference between stage of infiltration before and after treatment was statistically significant (p<0.002. High percentage of infiltration cells with positive anti Bcl-2 reaction from 42.0% in one patient to 85.33+/-3.06% in four patients before treatment was observed. After treatment percentage of infiltration cells with positive anti Bcl-2 antibody reaction was from 33.0+/-18.38% in two patients to 99.0% in one patient. Positive correlation between stage of infiltration and expression of Bcl-2 protein was confirmed before and after treatment. Such correlations were not observed in case of Bax and Bcl-x. Strong staining of immunohistochemical reaction of cells in lymphoid infiltration with Bcl-2 antibody was confirmed. There was a difference between Bcl-/Bax ratio before and after treatment. Immunohistochemical assessment of expression of Bcl-2 family proteins in cells of lymphoid infiltration in bone

  8. Immunohistochemical Study Of Bcl-2 Protein And Estrogen Receptor-Alpha Expression In Benign Prostatic Hyperplasia And Prostatic Carcinoma

    Directory of Open Access Journals (Sweden)

    Ahmed H. Abel-Rahman- Ghada A. Abdel-Aziz*- Ali Emad S** Abdel

    2004-12-01

    independent prognostic indicator (P < 0.05. Thus, the immunohistochemical expression of ER and Bcl-2 protein in prostatic tissue may aid in better understanding the biology and genesis of both prostatic hyperplasia and carcinoma .

  9. ROS-mediated lipopolysaccharide-induced apoptosis in INS-1 cells by modulation of Bcl-2 and Bax.

    Science.gov (United States)

    DU, S-C; Ge, Q-M; Lin, N; Dong, Y; Su, Q

    2012-01-01

    Overproduction of reactive oxygen species (ROS) or exhaustion of antioxidants may cause oxidative stress which is a major factor of defective insulin secretion and increases apoptosis of pancreatic β-cells in diabetes. So there comes a consideration of whether antioxidant strategies can be used to protect deterioration of the β-cells. In this study, we explored the mechanism of oxidative stress mediated lipopolysaccharide (LPS) induced apoptosis in insulin secreting (INS-1) cells from a rat pancreatic β-cell line. ROS was monitored by using intracellular ROS capture dihydroethidium (DHE) and dihydrorhodamine123 (DHR123). Apoptosis rate was measured by flow cytometry (FCM). The pro-apoptotic gene Bax and anti-apoptotic gene Bcl-2 were analysed by Western blot and RT-PCR. The results demonstrate that LPS-stimulated INS-1 cells manifest intensified intracellular fluorescence in both dose- and time- dependent manners. Apoptosis rate of LPS stimulated INS-1 cells is significantly increased by FCM, with a significant increase in Bax/Bcl-2 ratio revealed by Western blot and RT-PCR. Furthermore, α-lipoic acid (α-LA) inhibits LPS-induced apoptosis, but can not restore the function of glucose stimulated insulin secretion (GSIS) in INS-1 cells. PMID:22455982

  10. Bcl-2 associated athanogene 5 (Bag5) is overexpressed in prostate cancer and inhibits ER-stress induced apoptosis

    International Nuclear Information System (INIS)

    The Bag (Bcl-2 associated athanogene) family of proteins consists of 6 members sharing a common, single-copied Bag domain through which they interact with the molecular chaperone Hsp70. Bag5 represents an exception in the Bag family since it consists of 5 Bag domains covering the whole protein. Bag proteins like Bag1 and Bag3 have been implicated in tumor growth and survival but it is not known whether Bag5 also exhibits this function. Bag5 mRNA and protein expression levels were investigated in prostate cancer patient samples using real-time PCR and immunoblot analyses. In addition immunohistological studies were carried out to determine the expression of Bag5 in tissue arrays. Analysis of Bag5 gene expression was carried out using one-way ANOVA and Bonferroni’s Multiple Comparison test. The mean values of the Bag5 stained cells in the tissue array was analyzed by Mann-Whitney test. Functional studies of the role of Bag5 in prostate cancer cell lines was performed using overexpression and RNA interference analyses. Our results show that Bag5 is overexpressed in malignant prostate tissue compared to benign samples. In addition we could show that Bag5 levels are increased following endoplasmic reticulum (ER)-stress induction, and Bag5 relocates from the cytoplasm to the ER during this process. We also demonstrate that Bag5 interacts with the ER-resident chaperone GRP78/BiP and enhances its ATPase activity. Bag5 overexpression in 22Rv.1 prostate cancer cells inhibited ER-stress induced apoptosis in the unfolded protein response by suppressing PERK-eIF2-ATF4 activity while enhancing the IRE1-Xbp1 axis of this pathway. Cells expressing high levels of Bag5 showed reduced sensitivity to apoptosis induced by different agents while Bag5 downregulation resulted in increased stress-induced cell death. We have therefore shown that Bag5 is overexpressed in prostate cancer and plays a role in ER-stress induced apoptosis. Furthermore we have identified GRP78/BiP as a novel

  11. Bcl-2, Bax, and c-Fos expression correlates to RPE cell apoptosis induced by UV-light and daunorubicin

    DEFF Research Database (Denmark)

    Liang, Y G; Jorgensen, A G; Kaestel, C G; Wiencke, A K; Lui, G M; la Cour, M H; Röpke, C H; Nissen, Mogens Holst

    2000-01-01

    PURPOSE. The aim of this study was to determine the role of Bcl-2, Bcl-X L, Bax, and c-Fos in regulation of apoptosis, induced by ultraviolet-light A (UV-A) and daunorubicin (DNR), in retinal pigment epithelium (RPE) cells grown on bovine extracellular matrix (ECM)-coated or uncoated plastic dishes....... METHODS. Apoptosis in confluent RPE cells cultured on ECM-coated or uncoated dishes was induced by UV-A or DNR. Apoptosis was detected by 7-amino-actinomycin D labeling followed by flow cytometry and by terminal deoxy-transferase mediated X-dUTP nick end labeling (TUNEL). Cellular expression of Bcl-2, Bcl......-X L, Bax, and c-Fos was determined by the use of antibodies and flow cytometry, Western blot analysis, and immunocytochemical staining. RESULTS. Both UV-A and DNR induce apoptosis in human RPE cells in vitro. Human fetal RPE cells grown on ECM-coated dishes were significantly more resistant to UV-A or...

  12. EXPRESSIONS OF P53, PROLIFERATING CELL NUCLEAR ANITIGEN, BCL-2 PROTEIN AND THEIR SIGNIFICANCE IN SALIVARY ADENOID CYSTIC CARCINOMA

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Objective To study the effects of P53, PCNA, Bcl-2 protein and their relationship in salivary adenoid cystic carcinoma(SACC). Methods These proteins were examined by immunohistochemistry. Results Overexpressions of P53 and PCNA were revealed in ACC samples, they were higher than those in (polymorphous adenomas) PA, but expression of Bcl-2 protein was not different between ACC and PA. In 3 subtypes of ACC, expressions of 3 proteins were different. Conclusion Mutations of P53, Bcl-2 may be involed in the occurrence of SACC, expression of PCNA and mutation of P53 may coexist in the development of the SACC.

  13. BCL-2 family proteins as 5-Azacytidine-sensitizing targets and determinants of response in myeloid malignancies

    Science.gov (United States)

    Bogenberger, J M; Kornblau, S M; Pierceall, W E; Lena, R; Chow, D; Shi, C-X; Mantei, J; Ahmann, G; Gonzales, I M; Choudhary, A; Valdez, R; Camoriano, J; Fauble, V; Tiedemann, R E; Qiu, Y H; Coombes, K R; Cardone, M; Braggio, E; Yin, H; Azorsa, D O; Mesa, R A; Stewart, A K; Tibes, R

    2014-01-01

    Synergistic molecular vulnerabilities enhancing hypomethylating agents in myeloid malignancies have remained elusive. RNA-interference drug modifier screens identified antiapoptotic BCL-2 family members as potent 5-Azacytidine-sensitizing targets. In further dissecting BCL-XL, BCL-2 and MCL-1 contribution to 5-Azacytidine activity, siRNA silencing of BCL-XL and MCL-1, but not BCL-2, exhibited variable synergy with 5-Azacytidine in vitro. The BCL-XL, BCL-2 and BCL-w inhibitor ABT-737 sensitized most cell lines more potently compared with the selective BCL-2 inhibitor ABT-199, which synergized with 5-Azacytidine mostly at higher doses. Ex vivo, ABT-737 enhanced 5-Azacytidine activity across primary AML, MDS and MPN specimens. Protein levels of BCL-XL, BCL-2 and MCL-1 in 577 AML patient samples showed overlapping expression across AML FAB subtypes and heterogeneous expression within subtypes, further supporting a concept of dual/multiple BCL-2 family member targeting consistent with RNAi and pharmacologic results. Consequently, silencing of MCL-1 and BCL-XL increased the activity of ABT-199. Functional interrogation of BCL-2 family proteins by BH3 profiling performed on patient samples significantly discriminated clinical response versus resistance to 5-Azacytidine-based therapies. On the basis of these results, we propose a clinical trial of navitoclax (clinical-grade ABT-737) combined with 5-Azacytidine in myeloid malignancies, as well as to prospectively validate BH3 profiling in predicting 5-Azacytidine response. PMID:24451410

  14. BCL-2 family proteins as 5-Azacytidine-sensitizing targets and determinants of response in myeloid malignancies.

    Science.gov (United States)

    Bogenberger, J M; Kornblau, S M; Pierceall, W E; Lena, R; Chow, D; Shi, C-X; Mantei, J; Ahmann, G; Gonzales, I M; Choudhary, A; Valdez, R; Camoriano, J; Fauble, V; Tiedemann, R E; Qiu, Y H; Coombes, K R; Cardone, M; Braggio, E; Yin, H; Azorsa, D O; Mesa, R A; Stewart, A K; Tibes, R

    2014-08-01

    Synergistic molecular vulnerabilities enhancing hypomethylating agents in myeloid malignancies have remained elusive. RNA-interference drug modifier screens identified antiapoptotic BCL-2 family members as potent 5-Azacytidine-sensitizing targets. In further dissecting BCL-XL, BCL-2 and MCL-1 contribution to 5-Azacytidine activity, siRNA silencing of BCL-XL and MCL-1, but not BCL-2, exhibited variable synergy with 5-Azacytidine in vitro. The BCL-XL, BCL-2 and BCL-w inhibitor ABT-737 sensitized most cell lines more potently compared with the selective BCL-2 inhibitor ABT-199, which synergized with 5-Azacytidine mostly at higher doses. Ex vivo, ABT-737 enhanced 5-Azacytidine activity across primary AML, MDS and MPN specimens. Protein levels of BCL-XL, BCL-2 and MCL-1 in 577 AML patient samples showed overlapping expression across AML FAB subtypes and heterogeneous expression within subtypes, further supporting a concept of dual/multiple BCL-2 family member targeting consistent with RNAi and pharmacologic results. Consequently, silencing of MCL-1 and BCL-XL increased the activity of ABT-199. Functional interrogation of BCL-2 family proteins by BH3 profiling performed on patient samples significantly discriminated clinical response versus resistance to 5-Azacytidine-based therapies. On the basis of these results, we propose a clinical trial of navitoclax (clinical-grade ABT-737) combined with 5-Azacytidine in myeloid malignancies, as well as to prospectively validate BH3 profiling in predicting 5-Azacytidine response. PMID:24451410

  15. Effect of Bcl-2 rs956572 SNP on regional gray matter volumes and cognitive function in elderly males without dementia

    OpenAIRE

    Liu, Mu-En; Huang, Chu-Chung; Hwang, Jen-Ping; Yang, Albert C.; Tu, Pei-Chi; Yeh, Heng-Liang; Hong, Chen-Jee; Liou, Ying-Jay; Chen, Jin-Fan; Lin, Ching-Po; Tsai, Shih-Jen

    2011-01-01

    The Bcl-2 gene is a major regulator of neural plasticity and cellular resilience. A single-nucleotide polymorphism (SNP) in the Bcl-2 gene, Bcl-2 rs956572, significantly modulates the expression of Bcl-2 protein and cellular vulnerability to apoptosis. This study investigated the association between the Bcl-2 rs956572 SNP and brain structural abnormalities in non-demented elders, and to test the relationship between neuropsychological performance and regional gray matter (GM) volumes. Our sam...

  16. IMPORTANCE OF APOPTOSIS MARKERS (MDM2, BCL-2 AND Bax) IN CONVENTIONAL RENAL CELL CARCINOMA.

    Science.gov (United States)

    Saker, Z; Tsintsadze, O; Jiqia, I; Managadze, L; Chkhotua, A

    2015-12-01

    The goal of the current study was to analyze the expression of Bcl-2, MDM2 and Bax in benign and malignant renal tissue samples and assess their possible association with different clinical parameters. Prognostic significance of the markers in recurrence-free and cancer-specific survivals has also been evaluated. Activity of MDM2, Bcl-2 and Bax was evaluated in: 24 normal human kidney tissues resected from the patients of different ages (range: 21-80 years), and in 52 conventional RCC samples. Intensity of the markers' expression was compared between the groups and correlation was analyzed with different clinical parameters. Activity of anti-apoptotic MDM2 and Bcl-2 was significantly elevated while activity of pro-apoptotic Bax was decreased in RCC as compared with normal kidney tissues. Bax expression was positively correlated with patient age. Significant association has been detected between the evaluated markers and cancer clinical parameters like: tumor stage, grade, lymph node and distant metastases. The markers' activity was associates with the tumor morphological features, in particular: presence of tumor necrosis and microvascular invasion. Disease recurrence and 5-year patient survival were associated with the markers' activity. Cox regression analyses have shown that tumor size, pathological stage and grade are the risk factors for disease recurrence and patient death. Expression of MDM2 and Bcl-2 is significantly up-regulated, while Bax is down-regulated in RCC as compared with normal kidney tissue. Intensity of the markers'activities is associated with the tumor pathological and clinical parameters (stage, grade, lymph node and distant metastases, tumor recurrence and patient survival). Further studies with more patients and longer follow-up will uncover the clinical importance of the evaluated markers in RCC. PMID:26719546

  17. Mechanisms of arsenic trioxide induced apoptosis of human cervical cancer HeLa cells and protection by Bcl-2

    Institute of Scientific and Technical Information of China (English)

    邓友平; 林晨; 郑杰; 梁萧; 陈洁平; 付明; 肖培根; 吴旻

    1999-01-01

    It was recently reported that arsenic trioxide (As2O3) can induce complete remission in patients with acute promyelocytic leukemia (APL). In this present article, the biological effect of As2O3 on human cervical cancer HeLa cells and HeLa cells overexpressing Bcl-2 is studied. By MTT and colony forming ability assays, morphology alteration, flow cytometric analysis, DNA gel electrephoresis and in situ cell death detection (TUNEL), it was found that As2O3 inhibited the growth of HeLa cells and induced G2/M arrest and apoptosis of the cells. RT-PCR, Northern blot, Western blot analysis revealed that As2O3 induced HeLa cell apoptosis possibly via decreasing the expression of c-myc and viral genes. HeLa cells overexpressing Bcl-2 partly resist As2O3 induced apoptosis, which might be relative to preventing the cells from As2O3 caused G2/M block, downregulation of c-myc gene expression and inhibition of viral gene expression was also noted, However, it was found that As2O3 at a high concentratio

  18. 17β-Estradiol Inhibits Apoptosis in MCF-7 Cells, Inducing bcl-2 Expression via Two Estrogen-Responsive Elements Present in the Coding Sequence

    Science.gov (United States)

    Perillo, Bruno; Sasso, Annarita; Abbondanza, Ciro; Palumbo, Giuseppe

    2000-01-01

    We have found that 17β-estradiol induces bcl-2 transcription in human breast cancer MCF-7 cells. To identify cis-acting elements involved in this regulation, we have analyzed hormone responsiveness of transiently transfected reporter constructs containing the bcl-2 major promoter (P1). Hormone inducibility was observed only when either of two sequences, located within the bcl-2 coding region and showing one and two mutations with respect to the consensus estrogen-responsive element, were inserted downstream from the P1 promoter. Both sequences behaved as enhancers exclusively in cells expressing the estrogen receptor and were able to bind this receptor in in vitro assays. Transfections into MCF-7 cells of plasmids carrying a bcl-2 cDNA fragment which included these two elements revealed that their simultaneous presence resulted in an additive effect on reporter gene activity, whose size resembled the increase of endogenous bcl-2 mRNA level observed in untransfected cells after hormone treatment. Moreover, the identified elements were able to mediate up-regulation of bcl-2 expression by 17β-estradiol, since exogenous bcl-2 mRNA was induced by hormone challenge of MCF-7 cells transiently transfected with a vector containing the bcl-2 coding sequence cloned under the control of a non-estrogen-responsive promoter. Finally, we show that hormone prevention of apoptosis, induced by incubating MCF-7 cells with hydrogen peroxide, was strictly related to bcl-2 up-regulation. Our results indicate that the bcl-2 major promoter does not contain cis-acting elements directly involved in transcriptional control by 17β-estradiol and that hormone treatment inhibits programmed cell death in MCF-7 cells, inducing bcl-2 expression via two estrogen-responsive elements located within its coding region. PMID:10733592

  19. 17beta-estradiol inhibits apoptosis in MCF-7 cells, inducing bcl-2 expression via two estrogen-responsive elements present in the coding sequence.

    Science.gov (United States)

    Perillo, B; Sasso, A; Abbondanza, C; Palumbo, G

    2000-04-01

    We have found that 17beta-estradiol induces bcl-2 transcription in human breast cancer MCF-7 cells. To identify cis-acting elements involved in this regulation, we have analyzed hormone responsiveness of transiently transfected reporter constructs containing the bcl-2 major promoter (P(1)). Hormone inducibility was observed only when either of two sequences, located within the bcl-2 coding region and showing one and two mutations with respect to the consensus estrogen-responsive element, were inserted downstream from the P(1) promoter. Both sequences behaved as enhancers exclusively in cells expressing the estrogen receptor and were able to bind this receptor in in vitro assays. Transfections into MCF-7 cells of plasmids carrying a bcl-2 cDNA fragment which included these two elements revealed that their simultaneous presence resulted in an additive effect on reporter gene activity, whose size resembled the increase of endogenous bcl-2 mRNA level observed in untransfected cells after hormone treatment. Moreover, the identified elements were able to mediate up-regulation of bcl-2 expression by 17beta-estradiol, since exogenous bcl-2 mRNA was induced by hormone challenge of MCF-7 cells transiently transfected with a vector containing the bcl-2 coding sequence cloned under the control of a non-estrogen-responsive promoter. Finally, we show that hormone prevention of apoptosis, induced by incubating MCF-7 cells with hydrogen peroxide, was strictly related to bcl-2 up-regulation. Our results indicate that the bcl-2 major promoter does not contain cis-acting elements directly involved in transcriptional control by 17beta-estradiol and that hormone treatment inhibits programmed cell death in MCF-7 cells, inducing bcl-2 expression via two estrogen-responsive elements located within its coding region. PMID:10733592

  20. Selective peptide inhibitors of antiapoptotic cellular and viral Bcl-2 proteins lead to cytochrome c release during latent Kaposi’s sarcoma-associated herpesvirus infection

    OpenAIRE

    Burrer, Christine M.; Foight, Glenna W.; Keating, Amy E.; Chan, Gary C.

    2015-01-01

    Kaposi’s sarcoma-associated herpesvirus (KSHV) is associated with B-cell lymphomas including primary effusion lymphoma and multicentric Castleman’s disease. KSHV establishes latency within B cells by modulating or mimicking the antiapoptotic Bcl-2 family of proteins to promote cell survival. Our previous BH3 profiling analysis, a functional assay that assesses the contribution of Bcl-2 proteins towards cellular survival, identified two Bcl-2 proteins, cellular Mcl-1 and viral KsBcl-2, as pote...

  1. Expression of the bcl-2 oncogene protein is not specific for the 14;18 chromosomal translocation.

    OpenAIRE

    F. Pezzella(Istituto Nazionale di Fisica Nucleare, Sezione di Napoli, Complesso Universitario di Monte S. Angelo ed. 6, via Cintia, 80126 Napoli, Italy); Tse, A G; Cordell, J L; Pulford, K. A.; Gatter, K C; Mason, D Y

    1990-01-01

    It has been reported previously that the bcl-2 protooncogene protein is detectable in neoplastic cells from cases of human lymphoma in which the 14;18 chromosomal translocation is present, but not in lymphomas that lack this chromosomal rearrangement or in normal lymphoid tissue. In the present study we confirmed, by immunohistologic labeling with polyclonal and monoclonal antibodies, that bcl-2 protein is strongly expressed in many cases of follicular lymphoma and that these neoplastic folli...

  2. Plumbagin reduces chronic lymphocytic leukemia cell survival by downregulation of Bcl-2 but upregulation of the Bax protein level.

    Science.gov (United States)

    Fu, Chunling; Gong, Yanqing; Shi, Xuanxuan; Sun, Zengtian; Niu, Mingshan; Sang, Wei; Xu, Linyan; Zhu, Feng; Wang, Ying; Xu, Kailin

    2016-09-01

    Chronic lymphocytic leukemia (CLL) is the most common leukemia in Western countries, and mainly originates from an accumulation of abnormal B cells caused by the dysregulation of cell proliferation and apoptosis rates. The aberration of apoptosis-related genes in CLL cells results in defective apoptosis of CLL cells in response to traditional therapeutic medicine. Plumbagin (5-hydroxy-2-methyl-1, 4-naphthoquinone), a natural compound from Plumbago zeylinica, has been shown to exhibit pro-apoptotic activities in tumor cells. In the present study, we report that plumbagin effectively inhibited CLL cell viability with a lower dose compared to fludarabine, and inhibited cell proliferation in a dose-dependent manner. In addition, plumbagin promoted accumulation of MEC-1 cells in the S phase, and blocked cell cycle transition of HG3 cells from G0/G1 to S phase. Molecularly, plumbagin markedly induced CLL cell apoptosis through reduction of Bcl-2, but through an increase in the Bax protein level. These results suggest that plumbagin may be considered as a potential anticancer agent for CLL therapy. PMID:27461100

  3. High level of Bcl-2 counteracts apoptosis mediated by a live rabies virus vaccine strain and induces long-term infection

    International Nuclear Information System (INIS)

    We report here that rabies virus strains, currently used to immunize wildlife against rabies, induce not only caspase-dependent apoptosis in the human lymphoblastoid Jurkat T cell line (Jurkat-vect), but also a caspase-independent pathway involving the apoptosis-inducing factor (AIF). In contrast, a strain of neurotropic RV that does not induce apoptosis did not activate caspases or induce AIF translocation. Bcl-2 overproduction in Jurkat T cells (Jurkat-Bcl-2) abolished both pathways. ERA infection and production were similar in Jurkat-vect and Jurkat-Bcl-2 cells, indicating Bcl-2 has no direct antiviral effects. Bcl-2 production is naturally upregulated by day 3 in ERA-infected Jurkat-vect cultures. The increase in Bcl-2 levels seems to be controlled by the virus infection itself and results in the establishment of long-term, persistently infected cultures that continue to produce virus. Thus, in infections with live RV vaccine strains, infected cells may be productive reservoirs of virus in the long term. This may account for the high efficacy of live rabies vaccines

  4. Endothelium Expression of Bcl-2 Is Essential for Normal and Pathological Ocular Vascularization.

    Directory of Open Access Journals (Sweden)

    Ismail S Zaitoun

    Full Text Available Bcl-2 is an anti-apoptotic protein with important roles in vascular homeostasis and angiogenesis. Mice globally lacking Bcl-2 (Bcl-2 -/- are small in stature and succumb to renal failure shortly after weaning as a result of renal hypoplasia/cystic dysplasia. We have shown that Bcl-2 -/- mice displayed attenuated retinal vascular development and neovascularization. In vitro studies indicated that in addition to modulating apoptosis, Bcl-2 expression also impacts endothelial and epithelial cell adhesion, migration and extracellular matrix production. However, studies delineating the cell autonomous role Bcl-2 expression plays in the endothelium during vascular development, pruning and remodeling, and neovascularization are lacking. Here we generated mice carrying a conditional Bcl-2 allele (Bcl-2Flox/Flox and VE-cadherin-cre (Bcl-2EC mice. Bcl-2EC mice were of normal stature and lifespan and displayed some but not all of the retinal vascular defects previously observed in global Bcl-2 deficient mice. Bcl-2EC mice had decreased numbers of endothelial cells, decreased retinal arteries and premature primary branching of the retinal vasculature, but unlike the global knockout mice, spreading of the retinal superficial vascular layer proceeded normally. Choroidal neovascularization was attenuated in Bcl-2EC mice, although retinal neovascularization accompanying oxygen-induced ischemic retinopathy was not. Thus, Bcl-2 expression in the endothelium plays a significant role during postnatal retinal vascularization, and pathological choroidal but not retinal neovascularization, suggesting vascular bed specific Bcl-2 function in the endothelium.

  5. Endothelium Expression of Bcl-2 Is Essential for Normal and Pathological Ocular Vascularization.

    Science.gov (United States)

    Zaitoun, Ismail S; Johnson, Ryan P; Jamali, Nasim; Almomani, Reem; Wang, Shoujian; Sheibani, Nader; Sorenson, Christine M

    2015-01-01

    Bcl-2 is an anti-apoptotic protein with important roles in vascular homeostasis and angiogenesis. Mice globally lacking Bcl-2 (Bcl-2 -/-) are small in stature and succumb to renal failure shortly after weaning as a result of renal hypoplasia/cystic dysplasia. We have shown that Bcl-2 -/- mice displayed attenuated retinal vascular development and neovascularization. In vitro studies indicated that in addition to modulating apoptosis, Bcl-2 expression also impacts endothelial and epithelial cell adhesion, migration and extracellular matrix production. However, studies delineating the cell autonomous role Bcl-2 expression plays in the endothelium during vascular development, pruning and remodeling, and neovascularization are lacking. Here we generated mice carrying a conditional Bcl-2 allele (Bcl-2Flox/Flox) and VE-cadherin-cre (Bcl-2EC mice). Bcl-2EC mice were of normal stature and lifespan and displayed some but not all of the retinal vascular defects previously observed in global Bcl-2 deficient mice. Bcl-2EC mice had decreased numbers of endothelial cells, decreased retinal arteries and premature primary branching of the retinal vasculature, but unlike the global knockout mice, spreading of the retinal superficial vascular layer proceeded normally. Choroidal neovascularization was attenuated in Bcl-2EC mice, although retinal neovascularization accompanying oxygen-induced ischemic retinopathy was not. Thus, Bcl-2 expression in the endothelium plays a significant role during postnatal retinal vascularization, and pathological choroidal but not retinal neovascularization, suggesting vascular bed specific Bcl-2 function in the endothelium. PMID:26444547

  6. Photobiomodulation on Bax and Bcl-2 Proteins and SIRT1/PGC-1α Axis mRNA Expression Levels of Aging Rat Skeletal Muscle

    Directory of Open Access Journals (Sweden)

    Fang-Hui Li

    2014-01-01

    Full Text Available Objective. This study aimed to analyze the effects of low level laser irradiation (LLLI on Bax and IGF-1 and Bcl-2 protein contents and SIRT1/PGC-1α axis mRNA expression levels to prevent sarcopenia in aged rats. Material and Methods. Twenty female Sprague Dawley rats (18 months old were randomly divided into two groups (n=10 per group: control (CON and LLLI groups. The gallium-aluminum-arsenium (GaAlAs laser irradiation at 810 nm was used in the single point contact mode (3.75 J/cm2; 0.4 cm2; 125 mW/cm2; 30 s. Bax, Bcl-2, and IGF-1 proteins and SIRT1/PGC-1α axis mRNA expression were assessed 24 h after LLLI on gastrocnemius in aged rat. Results. Gastrocnemius muscle weights, gastrocnemius mass/body mass, Bcl-2/BAX ratio, Bcl-2 protein, IGF-1 protein, and the mRNA contents in SIRT1, PGC-1α, NRF1, TMF, and SOD2 were significantly (P<0.05 increased by LLLI compared to CON group without LLLI. However, levels of BAX protein and caspase 3 mRNA were significantly attenuated by LLLI compared to CON group (P<0.05. Conclusion. LLLI at 810 nm inhibits sarcopenia associated with upregulation of Bcl-2/BAX ratio and IGF-1 and SIRT1/PGC-1α axis mRNA expression in aged rats. This indicates that LLLI has potential to decrease progression of myocyte apoptosis in sarcopenic muscles.

  7. Photocontrolled Exposure of Pro-apoptotic Peptide Sequences in LOV Proteins Modulates Bcl-2 Family Interactions.

    Science.gov (United States)

    Mart, Robert J; Meah, Dilruba; Allemann, Rudolf K

    2016-04-15

    LOV domains act as biomolecular sensors for light, oxygen or the environment's redox potential. Conformational changes upon the formation of a covalent cysteinyl flavin adduct are propagated through hydrogen-bonding networks in the core of designed hybrid phototropin LOV2 domains that incorporate the Bcl homology region 3 (BH3) of the key pro-apoptotic protein BH3-interacting-domain death agonist (BID). The resulting change in conformation of a flanking amphiphilic α-helix creates a light-dependent optogenetic tool for the modulation of interactions with the anti-apoptotic B-cell leukaemia-2 (Bcl-2) family member Bcl-xL . PMID:26493687

  8. Functional Cooperation of the Proapoptotic Bcl2 Family Proteins Bmf and Bim In Vivo ▿

    OpenAIRE

    Hübner, Anette; Cavanagh-Kyros, Julie; Rincon, Mercedes; Richard A Flavell; Davis, Roger J

    2009-01-01

    Bcl2-modifying factor (Bmf) is a member of the BH3-only group of proapoptotic proteins. To test the role of Bmf in vivo, we constructed mice with a series of mutated Bmf alleles that disrupt Bmf expression, prevent Bmf phosphorylation by the c-Jun NH2-terminal kinase (JNK) on Ser74, or mimic Bmf phosphorylation on Ser74. We report that the loss of Bmf causes defects in uterovaginal development, including an imperforate vagina and hydrometrocolpos. We also show that the phosphorylation of Bmf ...

  9. Simultaneous gene silencing of Bcl-2, XIAP and Survivin re-sensitizes pancreatic cancer cells towards apoptosis

    International Nuclear Information System (INIS)

    Pancreatic ductal adenocarcinoma shows a distinct apoptosis resistance, which contributes significantly to the aggressive nature of this tumor and constrains the effectiveness of new therapeutic strategies. Apoptosis resistance is determined by the net balance of the cells pro-and anti-apoptotic 'control mechanisms'. Numerous dysregulated anti-apoptotic genes have been identified in pancreatic cancer and seem to contribute to the high anti-apoptotic buffering capacity. We aimed to compare the benefit of simultaneous gene silencing (SGS) of several candidate genes with conventional gene silencing of single genes. From literature search we identified the anti-apoptotic genes XIAP, Survivin and Bcl-2 as commonly upregulated in pancreatic cancer. We performed SGS and silencing of single candidate genes using siRNA molecules in two pancreatic cancer cell lines. Effectiveness of SGS was assessed by qRT-PCR and western blotting. Apoptosis induction was measured by flow cytometry and caspase activation. Simultaneous gene silencing reduced expression of the three target genes effectively. Compared to silencing of a single target or control, SGS of these genes resulted in a significant higher induction of apoptosis in pancreatic cancer cells. In the present study we performed a subliminal silencing of different anti-apoptotic target genes simultaneously. Compared to silencing of single target genes, SGS had a significant higher impact on apoptosis induction in pancreatic cancer cells. Thereby, we give further evidence for the concept of an anti-apoptotic buffering capacity of pancreatic cancer cells

  10. Simultaneous gene silencing of Bcl-2, XIAP and Survivin re-sensitizes pancreatic cancer cells towards apoptosis

    Directory of Open Access Journals (Sweden)

    Grützmann Robert

    2010-07-01

    Full Text Available Abstract Background Pancreatic ductal adenocarcinoma shows a distinct apoptosis resistance, which contributes significantly to the aggressive nature of this tumor and constrains the effectiveness of new therapeutic strategies. Apoptosis resistance is determined by the net balance of the cells pro-and anti-apoptotic "control mechanisms". Numerous dysregulated anti-apoptotic genes have been identified in pancreatic cancer and seem to contribute to the high anti-apoptotic buffering capacity. We aimed to compare the benefit of simultaneous gene silencing (SGS of several candidate genes with conventional gene silencing of single genes. Methods From literature search we identified the anti-apoptotic genes XIAP, Survivin and Bcl-2 as commonly upregulated in pancreatic cancer. We performed SGS and silencing of single candidate genes using siRNA molecules in two pancreatic cancer cell lines. Effectiveness of SGS was assessed by qRT-PCR and western blotting. Apoptosis induction was measured by flow cytometry and caspase activation. Results Simultaneous gene silencing reduced expression of the three target genes effectively. Compared to silencing of a single target or control, SGS of these genes resulted in a significant higher induction of apoptosis in pancreatic cancer cells. Conclusions In the present study we performed a subliminal silencing of different anti-apoptotic target genes simultaneously. Compared to silencing of single target genes, SGS had a significant higher impact on apoptosis induction in pancreatic cancer cells. Thereby, we give further evidence for the concept of an anti-apoptotic buffering capacity of pancreatic cancer cells.

  11. Effects of knocking out Bcl-2 gene on proliferation and apoptosis of human pancreatic cancer cells SW1990%Bcl-2基因敲除对人胰腺癌细胞增殖及凋亡的影响

    Institute of Scientific and Technical Information of China (English)

    魏莉; 张海文; 涂芊茜; 刘斌; 蔡宏剑; 孙春亮; 陈海涛

    2015-01-01

    目的 探讨Bcl-2基因对人胰腺癌SW1990细胞增殖及凋亡的影响.方法 设计并合成靶向Bcl-2基因的sgRNA(Bcl-2-sgRNA),通过CRISPR-Cas9系统将其结合到CRISPR载体Cas9,经测序验证后转染人胰腺癌细胞株SW1990,筛选Bcl-2基因敲除稳转细胞,以野生型SW1990细胞作为对照.采用CCK-8法测定细胞生长曲线,通过克隆形成实验计数细胞克隆数,运用流式细胞仪检测细胞周期及凋亡.结果 成功获得Bcl-2基因敲除的人胰腺癌SW1990细胞株,其Bcl-2蛋白表达缺失.与野生SW1990细胞比较,敲除Bcl-2基因的SW1990细胞的生长被抑制,细胞克隆形成数量显著减少[(160.7±10.0)个比(285.3±14.2)个],G1期细胞比例显著增加[(84.51±0.97)%比(57.49±1.08)%],S期细胞比例显著减少[(12.82±0.99)%比(27.56±1.65)%],细胞凋亡率显著增加[(12.67±0.59)%比(0.37±0.35)%],差异均有统计学意义(P值均<0.01).结论 敲除Bcl-2基因可抑制胰腺癌SW1990细胞的生长,降低细胞克隆形成能力,使细胞阻滞在G1期,并显著增加细胞凋亡率.%Objective To investigate the effect of Bcl-2 gene expression on the proliferation and apoptosis of human pancreatic cancer SW1990 cells.Methods Bcl-2 short guide RNA (Bcl-2-sgRNA) was designed and synthesized,and it was combined with CRISPR-Cas 9.After confirmation by gene sequencing,it was transfected into human pancreatic cancer cell line SW1990,then the cells with stable Bcl-2 gene knock-out were selected,and wild type SW1990 cells were used as control.The cell growth curve was determined by CCK-8 method.The number of clone formation was measured.Flow cytometry was used to measure cell cycle and apoptosis.Results Human pancreatic cancer cell line SW1990 with Bcl-2 gene knock-out was successful constructed.Compared with wild type SW1990 cells,the growth of SW1990 cells with Bcl-2 gene knock-out was inhibited,the number of clone formation was significantly decreased [(160.7 ± 10.0) vs (285.3

  12. Bcl-2 regulates HIF-1alpha protein stabilization in hypoxic melanoma cells via the molecular chaperone HSP90.

    Directory of Open Access Journals (Sweden)

    Daniela Trisciuoglio

    Full Text Available BACKGROUND: Hypoxia-Inducible Factor 1 (HIF-1 is a transcription factor that is a critical mediator of the cellular response to hypoxia. Enhanced levels of HIF-1alpha, the oxygen-regulated subunit of HIF-1, is often associated with increased tumour angiogenesis, metastasis, therapeutic resistance and poor prognosis. It is in this context that we previously demonstrated that under hypoxia, bcl-2 protein promotes HIF-1/Vascular Endothelial Growth Factor (VEGF-mediated tumour angiogenesis. METHODOLOGY/PRINCIPAL FINDINGS: By using human melanoma cell lines and their stable or transient derivative bcl-2 overexpressing cells, the current study identified HIF-1alpha protein stabilization as a key regulator for the induction of HIF-1 by bcl-2 under hypoxia. We also demonstrated that bcl-2-induced accumulation of HIF-1alpha protein during hypoxia was not due to an increased gene transcription or protein synthesis. In fact, it was related to a modulation of HIF-1alpha protein expression at a post-translational level, indeed its degradation rate was faster in the control lines than in bcl-2 transfectants. The bcl-2-induced HIF-1alpha stabilization in response to low oxygen tension conditions was achieved through the impairment of ubiquitin-dependent HIF-1alpha degradation involving the molecular chaperone HSP90, but it was not dependent on the prolyl hydroxylation of HIF-1alpha protein. We also showed that bcl-2, HIF-1alpha and HSP90 proteins form a tri-complex that may contribute to enhancing the stability of the HIF-1alpha protein in bcl-2 overexpressing clones under hypoxic conditions. Finally, by using genetic and pharmacological approaches we proved that HSP90 is involved in bcl-2-dependent stabilization of HIF-1alpha protein during hypoxia, and in particular the isoform HSP90beta is the main player in this phenomenon. CONCLUSIONS/SIGNIFICANCE: We identified the stabilization of HIF-1alpha protein as a mechanism through which bcl-2 induces the

  13. Bcl-2 Regulates HIF-1α Protein Stabilization in Hypoxic Melanoma Cells via the Molecular Chaperone HSP90

    Science.gov (United States)

    Trisciuoglio, Daniela; Gabellini, Chiara; Desideri, Marianna; Ziparo, Elio; Zupi, Gabriella; Del Bufalo, Donatella

    2010-01-01

    Background Hypoxia-Inducible Factor 1 (HIF-1) is a transcription factor that is a critical mediator of the cellular response to hypoxia. Enhanced levels of HIF-1α, the oxygen-regulated subunit of HIF-1, is often associated with increased tumour angiogenesis, metastasis, therapeutic resistance and poor prognosis. It is in this context that we previously demonstrated that under hypoxia, bcl-2 protein promotes HIF-1/Vascular Endothelial Growth Factor (VEGF)-mediated tumour angiogenesis. Methodology/Principal Findings By using human melanoma cell lines and their stable or transient derivative bcl-2 overexpressing cells, the current study identified HIF-1α protein stabilization as a key regulator for the induction of HIF-1 by bcl-2 under hypoxia. We also demonstrated that bcl-2-induced accumulation of HIF-1α protein during hypoxia was not due to an increased gene transcription or protein synthesis. In fact, it was related to a modulation of HIF-1α protein expression at a post-translational level, indeed its degradation rate was faster in the control lines than in bcl-2 transfectants. The bcl-2-induced HIF-1α stabilization in response to low oxygen tension conditions was achieved through the impairment of ubiquitin-dependent HIF-1α degradation involving the molecular chaperone HSP90, but it was not dependent on the prolyl hydroxylation of HIF-1α protein. We also showed that bcl-2, HIF-1α and HSP90 proteins form a tri-complex that may contribute to enhancing the stability of the HIF-1α protein in bcl-2 overexpressing clones under hypoxic conditions. Finally, by using genetic and pharmacological approaches we proved that HSP90 is involved in bcl-2-dependent stabilization of HIF-1α protein during hypoxia, and in particular the isoform HSP90β is the main player in this phenomenon. Conclusions/Significance We identified the stabilization of HIF-1α protein as a mechanism through which bcl-2 induces the activation of HIF-1 in hypoxic tumour cells involving the

  14. Effect of medroxyprogesterone acetate on K562/AO2 cells and P - gp, Bcl - 2 resistance protein expression%甲孕酮对K562/AO2细胞及P-gp、Bcl-2耐药蛋白表达的影响

    Institute of Scientific and Technical Information of China (English)

    王双

    2014-01-01

    Objective:To investigate the effect of MPA on leukemia K562 / AO2 cell apoptosis rate and expression of P -gp,Bcl - 2 resistance protein. Methods:To inhibit the proliferation of tumor cells was detected by MTT rate,to detect the ex-pression of P - gp and Bcl - 2 tumor cell apoptosis,flow cytometry. Results:MPA can improve the K562 / AO2 cell apoptosis, downregulate the expression of K562 / AO2 cells P - gp,Bcl - 2. Conclusion:MPA can improve the chemotherapeutic sensitivi-ty of K562 / AO2 cell,promote the apoptosis of reversal of multidrug resistance,have certain effect on K562 / AO2 cells.%目的:探讨甲孕酮对白血病 K562/ AO2细胞凋亡率及 P - gp、Bcl -2耐药蛋白表达的影响。方法以 MTT法检测肿瘤细胞增殖的抑制率,流式细胞术检测肿瘤细胞凋亡、P - gp 及 Bcl -2表达。结果甲孕酮能够提高 K562/AO2细胞的凋亡,能够下调 K562/ AO2细胞 P - gp、Bcl -2的表达。结论甲孕酮能提高 K562/ AO2细胞化疗敏感性,促进其凋亡,对 K562/ AO2细胞有一定的逆转耐药作用。

  15. The bcl-2 mRNA Expression in GCDC-induced Obstructive Jaundice in Rats and Its Implication in Hepatocellular Apoptosis

    Institute of Scientific and Technical Information of China (English)

    王剑明; 邹声泉

    2002-01-01

    The modulatory role of bcl-2 gene in hepatocellular apoptosis of rats with glycochenodeoxycholate (GCDC)-induced obstructive jaundice was investigated. The hepatocytes in normal rats and those with bile duct-ligation for 7 days, 14 days and 21 days were isolated and obtained by in situ collagenase perfusion and primary culture. The expression of bcl-2 mRNA in the hepatocytes was detected by RT-PCR. Primary culture was performed on the hepatocytes from normal rats and those with bile duct-ligation for 14 days. 100 μmol/L GCDC was added to the hepatocytes for incubation for 24 h. The hepatocellular apoptotic ratio was measured by using FCM and hepatocellular apoptosis detected in situ by using TUNEL technique. Results showed that the expression of bcl-2 mRNA was not detectable in the hepatocytes of normal rats by RT-PCR technique, while detectable in the hepatocytes of those with bile duct ligation (BDL) for 7, 14 and 21 days. Hepatocellular apoptosis in the BDL group was obviously decreased as compared with normal control group after addition of 100μmol/L GCDC to the cells for 24 h. It was concluded that the hepatocytes in the BDL rats expressed bcl-2. During obstructive jaundice, expression of bcl-2 from the hepatocytes can inhibit the bile saltinduced hepatocellular apoptosis.

  16. Rapid acclimation of juvenile corals to CO2 -mediated acidification by upregulation of heat shock protein and Bcl-2 genes.

    Science.gov (United States)

    Moya, A; Huisman, L; Forêt, S; Gattuso, J-P; Hayward, D C; Ball, E E; Miller, D J

    2015-01-01

    Corals play a key role in ocean ecosystems and carbonate balance, but their molecular response to ocean acidification remains unclear. The only previous whole-transcriptome study (Moya et al. Molecular Ecology, 2012; 21, 2440) documented extensive disruption of gene expression, particularly of genes encoding skeletal organic matrix proteins, in juvenile corals (Acropora millepora) after short-term (3 d) exposure to elevated pCO2 . In this study, whole-transcriptome analysis was used to compare the effects of such 'acute' (3 d) exposure to elevated pCO2 with a longer ('prolonged'; 9 d) period of exposure beginning immediately post-fertilization. Far fewer genes were differentially expressed under the 9-d treatment, and although the transcriptome data implied wholesale disruption of metabolism and calcification genes in the acute treatment experiment, expression of most genes was at control levels after prolonged treatment. There was little overlap between the genes responding to the acute and prolonged treatments, but heat shock proteins (HSPs) and heat shock factors (HSFs) were over-represented amongst the genes responding to both treatments. Amongst these was an HSP70 gene previously shown to be involved in acclimation to thermal stress in a field population of another acroporid coral. The most obvious feature of the molecular response in the 9-d treatment experiment was the upregulation of five distinct Bcl-2 family members, the majority predicted to be anti-apoptotic. This suggests that an important component of the longer term response to elevated CO2 is suppression of apoptosis. It therefore appears that juvenile A. millepora have the capacity to rapidly acclimate to elevated pCO2 , a process mediated by upregulation of specific HSPs and a suite of Bcl-2 family members. PMID:25444080

  17. The Action of Bcl-2 Apoptotic Family Proteins and Caspases in Mediating Follicle Atresia in Adult Mouse

    Directory of Open Access Journals (Sweden)

    Liliana Petculescu-Ciochină

    2011-05-01

    Full Text Available Among follicles present on the surface of the ovary only a small part reach ovulation, the majority entering atresia, which is an apoptotic process regulated hormonally in general. Apoptosis (from greek: apo = from, ptosis = falling - is a normal physiological process, genetically programmed cell death, which carries energy consumption by activating a program of internal suicide. This occurs at each stage of follicular development and is accompanied by a significant reduction in the number of follicles present at birth. Development stage-dependent mechanisms coordinate the evolution of follicles, leading to ovulation of a very small number of them. At follicular level apoptosis involves many morphological and biochemical processes that are based on pro-and anti-apoptotic members of Bcl-2 family of proteins (located on mitochondrial outer membrane and caspases. These changes aim internucleosomal DNA fragmentation, cell retraction followed by its wrinkling, cytoskeleton disruption, preservation of cytoplasmic organelles structure and function, loss of intercellular ties with the reduced expression of conexine 43 (key protein of communication junctions between granulose cells, progressive fragmentation of nucleus and cytoplasm, and finally the appearance of apoptotic bodies, and their inclusion by phagocytes, without the involvement of any inflammatory response.

  18. Apoptosis and the activity of ceramide, Bax and Bcl-2 in the lungs of neonatal rats exposed to limited and prolonged hyperoxia

    Directory of Open Access Journals (Sweden)

    Bitar Fadi F

    2006-07-01

    Full Text Available Abstract Background The aim of the study is to examine the effect of limited and prolonged hyperoxia on neonatal rat lung. This is done by examining the morphologic changes of apoptosis, the expression of ceramide, an important mediator of apoptosis, the expression of inflammatory mediators represented by IL-1β and the expression of 2 proto-oncogenes that appear to modulate apoptosis (Bax and Bcl-2. Methods Newborn rats were placed in chambers containing room air or oxygen above 90% for 7 days. The rats were sacrificed at 3, 7 or 14 days and their lungs removed. Sections were fixed, subjected to TUNEL, Hoechst, and E-Cadherin Staining. Sections were also incubated with anti-Bcl-2 and anti-Bax antisera. Bcl-2 and Bax were quantitated by immunohistochemistry. Lipids were extracted, and ceramide measured through a modified diacylglycerol kinase assay. RT-PCR was utilized to assess IL-1β expression. Results TUNEL staining showed significant apoptosis in the hyperoxia-exposed lungs at 3 days only. Co-staining of the apoptotic cells with Hoechst, and E-Cadherin indicated that apoptotic cells were mainly epithelial cells. The expression of Bax and ceramide was significantly higher in the hyperoxia-exposed lungs at 3 and 14 days of age, but not at 7 days. Bcl-2 was significantly elevated in the hyperoxia-exposed lungs at 3 and 14 days. IL-1β expression was significantly increased at 14 days. Conclusion Exposure of neonatal rat lung to hyperoxia results in early apoptosis documented by TUNEL assay. The early rise in Bax and ceramide appears to overcome the anti-apoptotic activity of Bcl-2. Further exposure did not result in late apoptotic changes. This suggests that apoptotic response to hyperoxia is time sensitive. Prolonged hyperoxia results in acute lung injury and the shifting balance of ceramide, Bax and Bcl-2 may be related to the evolution of the inflammatory process.

  19. Phyllanthus amarus inhibits cell growth and induces apoptosis in Dalton's lymphoma ascites cells through activation of caspase-3 and downregulation of Bcl-2.

    Science.gov (United States)

    Harikumar, Kuzhuvelil B; Kuttan, Girija; Kuttan, Ramadasan

    2009-06-01

    The authors found in an earlier study that Phyllanthus amarus extract could significantly inhibit the solid and ascites tumor development in mice induced by Dalton's lymphoma ascites (DLA) cells. In the present study, the apoptotic effects of P. amarus against DLA cells in culture was evaluated. P. amarus produced significant reduction in cell viability as determined by the MTT assay. It also induces the formation of apoptotic bodies with characteristic features like plasma membrane invagination, elongation, fragmentation, and chromatin condensation. P. amarus at concentrations of 100 and 200 microg/mL is shown to induce DNA fragmentation. Gene expression analysis reveals that P. amarus induces the expression of caspase-3 and inhibits the expression of Bcl-2, which is an antiapoptotic protein. So the present study provides some insights into the possible mechanism by which P. amarus brings about apoptosis and growth inhibition in DLA cells. PMID:19223368

  20. Bcl-2 protein expression in lung cancer and close correlation with neuroendocrine differentiation.

    OpenAIRE

    Jiang, S. X.; Kameya, T.; Sato, Y.; Yanase, N.; Yoshimura, H.; Kodama, T

    1996-01-01

    For determination of the cellular distribution of bcl-2 expression in lung cancer and clarification of its correlation with cell neuroendocrine differentiation, Bcl-2 immunostaining was carried out on a large series of formalin-fixed, paraffin-embedded lung cancer samples, and four general neuroendocrine marker and seven peptide hormone stainings were carried out on all Bcl-2-positive squamous cell carcinomas and adenocarcinomas of the lung as well as on 8 pulmonary neuroendocrine carcinomas ...

  1. BCL2 suppresses PARP1 function and non-apoptotic cell death

    OpenAIRE

    Dutta, Chaitali; Day, Tovah; Kopp, Nadja; van Bodegom, Diederik; Davids, Matthew S.; Ryan, Jeremy; Bird, Liat; Kommajosyula, Naveen; Weigert, Oliver; Yoda, Akinori; Fung, Hua; Brown, Jennifer R; Shapiro, Geoffrey I.; Letai, Anthony; Weinstock, David M.

    2012-01-01

    BCL2 suppresses apoptosis by binding the BH3 domain of pro-apoptotic factors and thereby regulating outer mitochondrial membrane permeabilization. Many tumor types, including B-cell lymphomas and chronic lymphocytic leukemia, are dependent on BCL2 for survival, but become resistant to apoptosis after treatment. Here we identified a direct interaction between the anti-apoptotic protein BCL2 and the enzyme poly(ADP) ribose polymerase 1 (PARP1), which suppresses PARP1 enzymatic activity and inhi...

  2. Expression of the apoptosis-related genes BCL-2 and BAD in human breast carcinoma and their associated relationship with chemosensitivity

    Directory of Open Access Journals (Sweden)

    Fan Yuan-ming

    2010-08-01

    BAD positive cancer cells. A positive correlation was found between expression of BAD and chemosensitivity for Epirubicin. Conclusion The expression of BCL-2 and BAD can be used as prognosis factors of breast cancer. Detection of the BCL-2 protein expression level, particularly, combined with the detection of the expression of BCL-2 and BAD as well as ER and PR were helpful in confirming the prognosis of breast carcinoma. The combined detection of BCL-2 and BAD may be markers for predicting the responses to anticancer drugs.

  3. EXPRESSION AND SIGNIFICANCE OF bcl-2 FAMILY IN AMELOBLASTONA

    Institute of Scientific and Technical Information of China (English)

    WANG Jie; MA Jie; ZHONG Ming; LIU Jing-dong

    2006-01-01

    Objective: To study the expression of bcl-2 and bax in human ameloblastoma (AB), and investigate the role of apoptosis in genesis and development of AB and the relation of apoptosis with the clinic biological characteristics of AB. Methods:BCL-2 and BAX proteins were detected in 75 cases of AB (primary AB 31 cases, recurrent AB 37 cases, malignant AB 7cases) by S-P method. Oral normal mucosa (NOM) and Odontogenic kerotosyst (OKC) were used as controls. Bcl-2 and bax mRNA in 20 cases of AB, 12 cases of OKC were detected by in situ hybridization. Results: The positive ratio of BCL-2protein was 88.0% ( 66/75 ) in AB, 74.3% (26/35) in OKC and 44.4% (4/9) in NOM, respectively (P<0.001). BCL-2 protein was expressed in peripheral cells and a few scattered stellate-shape cells in AB. The positive ratio of BAX protein was 74.7%(56/75)in AB, 65.7%(23/35)in OKC and 77.8%(7/9) in NOM, respectively (P<0.001). BAX protein was expressed in peripheral cells and stellate-shape cells with similar intensity. BCL-2 expression increased in recurrent and AB canceration(P<0.01), while for BAX expression, the positive ratio was higher in recurrent AB, but lower than that of malignant AB. A moderate negative correlation between BCL-2 and BAX protein was found (rk=-0.331, P<0.001).Conclusion: AB has much more apoptosis-inhibiting protein than apoptosis- accelarating protein. Apoptosis plays an important role in genesis, development of AB. The fashion and intensity of bcl-2 and bax expression were different in various tissues and in benign or malignant AB.

  4. Homologous recombination in mammalian cells: effect of p53 and Bcl-2 proteins, replication inhibition and ionizing radiations

    International Nuclear Information System (INIS)

    The control of cell cycle, associated with the mechanisms of replication, DNA repair/recombination allows the cells to maintain their genetic integrity. The p53 protein ensures the control of G1/S transition. Its inactivation would allow to initial replication on damaged matrix and lead to the block of replication forks followed by DNA strand breaks, good substrates for recombination. This work shows that the expression of mutant p53 protein stimulates both spontaneous and radio-induced homologous recombination, independently of the control of cell cycle. Moreover, the use of a set of replication inhibitors show that inhibition of the replication elongation stimulates recombination more strongly than the initiation inhibition. Replication arrest by these inhibitors also significantly increases the number of DNA strand breaks. These results highlighted a point of action of p53 protein on the ultimate stages of the homologous recombination mechanism. Lastly, the expression of Bcl-2 protein inhibits apoptosis and increases survival, but specifically inhibits conservative recombination, after radiation as well as in absence of apoptotic stress. The extinction of this mechanism of DNA repair is associated with an increase of mutagenesis. Taken together, these results allow ta consider the maintenance of the genetic stability as a cellular network involving different pathways. A multiple stages model for tumoral progression can be deduced. (author)

  5. Expressions of bcl-2 and P53 protein in Bowen's disease%Bowen病bcl-2及P53蛋白的表达

    Institute of Scientific and Technical Information of China (English)

    张士发; 王良明; 赵丽萍; 许静; 顾绍裘

    2004-01-01

    目的:探讨bcl-2及P53蛋白在Bowen病及Bowen样鳞癌中的表达及其意义.方法:应用免疫组织化学技术对11例Bowen病及3例Bowen样鳞癌bcl-2和/或P53蛋白的表达进行了检测.结果:11例Bowen病中bcl-2蛋白阳性2例(18%),P53蛋白阳性3例(27%);3例Bowen样鳞癌均见bcl-2蛋白表达.Bowen病中bcl-2与P53蛋白表达显著正相关(r=0.769,P<0.05).结论:Bowen病中bcl-2蛋白表达与P53基因突变有关,并参与了Bowen病的进展及向Bowen样鳞癌的演变.

  6. Melatonin may play a role in modulation of bax and bcl-2 expression levels to protect rat peripheral blood lymphocytes from gamma irradiation-induced apoptosis

    International Nuclear Information System (INIS)

    The close relationship between free radicals effects and apoptosis process has been proved. Melatonin has been reported as a direct free radical scavenger. We investigated the capability of melatonin in the modification of radiation-induced apoptosis and apoptosis-associated upstream regulators expression in rat peripheral blood lymphocytes. Rats were irradiated with a single whole body Cobalt 60-gamma radiation dose of 8 Gy at a dose rate of 101 cGy/min with or without melatonin pretreatments at different concentrations of 10 and 100 mg/kg body weight. The rats were divided into eight groups of control, irradiation-only, vehicle-only, vehicle plus irradiation, 10 mg/kg melatonin alone, 10 mg/kg melatonin plus irradiation, 100 mg/kg melatonin alone and 100 mg/kg melatonin plus irradiation. Rats were given an intraperitoneal (IP) injection of melatonin or the same volume of vehicle alone 1 h prior to irradiation. Blood samples were taken 4, 24, 48 and 72 h after irradiation for evaluation of flow cytometric analysis of apoptotic lymphocytes using Annexin V/PI assay and measurement of bax and bcl-2 expression using quantitative real-time PCR (RT2qPCR). Irradiation-only and vehicle plus irradiation showed an increase in the percentage of apoptotic lymphocytes significantly different from control group (P < 0.01), while melatonin pretreatments in a dose-dependent manner reduced it as compared with the irradiation-only and vehicle plus irradiation groups (P < 0.01) in all time points. This reduced apoptosis by melatonin was related to the downregulation of bax, upregulation of bcl-2, and therefore reduction of bax/bcl-2 ratio. Our results suggest that melatonin in these doses may provide modulation of bax and bcl-2 expression as well as bax/bcl-2 ratio to protect rat peripheral blood lymphocytes from gamma irradiation-induced apoptosis.

  7. Melatonin may play a role in modulation of bax and bcl-2 expression levels to protect rat peripheral blood lymphocytes from gamma irradiation-induced apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Mohseni, Mehran [Department of Radiology and Medical Physics, Faculty of Paramedicine, Kashan University of Medical Sciences, Kashan (Iran, Islamic Republic of); Mihandoost, Ehsan, E-mail: mihandoost.e@gmail.com [Department of Medical Radiation Engineering, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Shirazi, Alireza [Department of Medical Physics and Biomedical Engineering, Faculty of Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Sepehrizadeh, Zargham [Department of Pharmaceutical Biotechnology, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Bazzaz, Javad Tavakkoly [Department of Medical Genetics, Faculty of Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Ghazi-khansari, Mahmoud [Department of Pharmacology, Faculty of Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of)

    2012-10-15

    The close relationship between free radicals effects and apoptosis process has been proved. Melatonin has been reported as a direct free radical scavenger. We investigated the capability of melatonin in the modification of radiation-induced apoptosis and apoptosis-associated upstream regulators expression in rat peripheral blood lymphocytes. Rats were irradiated with a single whole body Cobalt 60-gamma radiation dose of 8 Gy at a dose rate of 101 cGy/min with or without melatonin pretreatments at different concentrations of 10 and 100 mg/kg body weight. The rats were divided into eight groups of control, irradiation-only, vehicle-only, vehicle plus irradiation, 10 mg/kg melatonin alone, 10 mg/kg melatonin plus irradiation, 100 mg/kg melatonin alone and 100 mg/kg melatonin plus irradiation. Rats were given an intraperitoneal (IP) injection of melatonin or the same volume of vehicle alone 1 h prior to irradiation. Blood samples were taken 4, 24, 48 and 72 h after irradiation for evaluation of flow cytometric analysis of apoptotic lymphocytes using Annexin V/PI assay and measurement of bax and bcl-2 expression using quantitative real-time PCR (RT{sup 2}qPCR). Irradiation-only and vehicle plus irradiation showed an increase in the percentage of apoptotic lymphocytes significantly different from control group (P < 0.01), while melatonin pretreatments in a dose-dependent manner reduced it as compared with the irradiation-only and vehicle plus irradiation groups (P < 0.01) in all time points. This reduced apoptosis by melatonin was related to the downregulation of bax, upregulation of bcl-2, and therefore reduction of bax/bcl-2 ratio. Our results suggest that melatonin in these doses may provide modulation of bax and bcl-2 expression as well as bax/bcl-2 ratio to protect rat peripheral blood lymphocytes from gamma irradiation-induced apoptosis.

  8. BEX1 Promotes Imatinib-Induced Apoptosis by Binding to and Antagonizing BCL-2

    OpenAIRE

    Qian Xiao; Yeting Hu; Yue Liu; Zhanhuai Wang; Haitao Geng; Lifeng Hu; Dengyong Xu; Ke Wang; Lei Zheng; Shu Zheng; Kefeng Ding

    2014-01-01

    An enhanced anti-apoptotic capacity of tumor cells plays an important role in the process of breakpoint cluster region/Abelson tyrosine kinase gene (BCR/ABL)-independent imatinib resistance. We have previously demonstrated that brain expressed X-linked 1 (BEX1) was silenced in secondary imatinib-resistant K562 cells and that re-expression of BEX1 can restore imatinib sensitivity resulting in the induction of apoptosis. However, the mechanism by which BEX1 executes its pro-apoptotic function r...

  9. Puerarin Attenuates Anoxia/Reoxygenation Injury Through Enhancing Bcl-2 Associated Athanogene 3 Expression, a Modulator of Apoptosis and Autophagy.

    Science.gov (United States)

    Ma, Yayu; Gai, Ya; Yan, Jingpeng; Li, Jian; Zhang, Yangyang

    2016-01-01

    BACKGROUND Puerarin has protective effects on ischemia-reperfusion injury, but the underlying mechanisms are not fully revealed. This study explored the effect of puerarin on the expression of Bcl-2 associated athanogene 3 (BAG3) in an in vitro model of anoxia/reoxygenation injury (A/RI) in neonate rat primary cardiomyocytes and the functions of BAG3 in A/RI. MATERIAL AND METHODS BAG3 expression in cardiomyocytes with or without puerarin pre-treatment was quantified using qRT-PCR and Western blot analysis. The effects of BAG3 on A/RI were studied by measuring the activity of lactate dehydrogenase (LDH) and creatine phosphate kinase (CPK), the concentration of malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px). The effects of BAG3 on autophagy and apoptosis of the cardiomyocytes after A/RI were further studied. RESULTS Puerarin significantly promoted BAG3 expression in the rat primary cardiomyocytes after A/RI. Enforced BAG3 expression presented similar effects as puerarin pre-treatment in attenuating A/RI in terms of CPK, LDH, MDA, SOD, GSH-Px, ROS generation, and cell viability. BAG3 overexpression significantly stimulated autophagy in cardiomyocytes after A/RI, which presented protective effects on A/RI in terms of cell viability and apoptosis. Autophagy inhibition partly abrogated the protective effects of BAG3. CONCLUSIONS Puerarin can directly increase BAG3 transcription and translation in cardiomyocytes after A/RI. The elevated BAG3 expression presents protective effects on A/RI at least through enhancing autophagy and reducing apoptosis, which is a novel protective mechanism of puerarin in ARI. PMID:27011313

  10. Expression of anti-apoptotic protein Bcl-2 and pro-apoptotic protein Bax after delayed paraplegia induced by ischemia/reperfusion injury

    Institute of Scientific and Technical Information of China (English)

    Bibo Liu; Miao Liu; Duoning Wang; Wei Ma; Shengli Dang

    2006-01-01

    BACKGROUND:Operation of spine does not involve in spinal cord;however,spinal cord injury occurs at post-operation induced by unclear factors.Meanwhile,after decompression of lumbar spinal canal,symptoms are severer and severer.In addition,during extirpation of oervical and lumbar intervertabral disc,spinal cord and its vessels are not damaged,but spinal cord injury is also suffered from patients with partial improvement.All statuses mentioned above are related to expressed changes of bc/-2 gene inhibiting apoptosis and bax gene accelerating apoptosis.OBJECTIVE:To observe motor function of hindlimbs of ischemia/reperfusion model in rabbits at various time points after reperfusion and expressions of apoptosis correlated protein Bcl-2 and Bax.DESIGN:Completely randomized grouping design and contrast study.SEITING:Department of Orthopedics,the First Affiliated Hospital of Medical School,Xi'an Jiao Tong University.MATERIALS:Forty-eight New Zealand white rabbits of both genders were randomly divided into sham operation group(n=24) and model group(n=24),and then,rabbits in each group were observed at four time points:8,24,72 and 168 hours after reperfusion,with 6 in each time point.Rabbit-anti-rabbit Bcl-2 antibody and rabbit-anti-rabbit Bax antibody were provided by Boster Company.The procedures were accordant to the METHODS:The experiment was carried out at Laboratory of Orthopaedics of First Affiliated Hospital of Medical School,Xi'an Jiao Tong University from April to August 2005.①Delayed paralysis models of spinal cord after ischemia/reperfusion were established based on method of Zivin et al.Animals in sham operation group underwent an exposure of abdominal aorta but the aorta was not occluded.②Motor function of hindlimb was observed 8,24,72 and 168 hours after reperfusion.A grade of 0-5 was assigned to each animal (grade 0:no voluntary hind limb function;grade 5:normal hop;grades 0-3:paraplegia).③The lumbar segment of the spinal cord(L3 to L5)was used for

  11. A surface groove essential for viral bcl-2 function during chronic infection in vivo.

    Directory of Open Access Journals (Sweden)

    2005-09-01

    Full Text Available Antiapoptotic Bcl-2 family proteins inhibit apoptosis in cultured cells by binding BH3 domains of proapoptotic Bcl-2 family members via a hydrophobic BH3 binding groove on the protein surface. We investigated the physiological importance of the BH3 binding groove of an antiapoptotic Bcl-2 protein in mammals in vivo by analyzing a viral Bcl-2 family protein. We show that the gamma-herpesvirus 68 (gammaHV68 Bcl-2 family protein (gammaHV68 v-Bcl-2, which is known to inhibit apoptosis in cultured cells, inhibits both apoptosis in primary lymphocytes and Bax toxicity in yeast. Nuclear magnetic resonance determination of the gammaHV68 v-Bcl-2 structure revealed a BH3 binding groove that binds BH3 domain peptides from proapoptotic Bcl-2 family members Bax and Bak via a molecular mechanism shared with host Bcl-2 family proteins, involving a conserved arginine in the BH3 peptide binding groove. Mutations of this conserved arginine and two adjacent amino acids to alanine (SGR to AAA within the BH3 binding groove resulted in a properly folded protein that lacked the capacity of the wild-type gammaHV68 v-Bcl-2 to bind Bax BH3 peptide and to block Bax toxicity in yeast. We tested the physiological importance of this v-Bcl-2 domain during viral infection by engineering viral mutants encoding a v-Bcl-2 containing the SGR to AAA mutation. This mutation resulted in a virus defective for both efficient reactivation of gammaHV68 from latency and efficient persistent gammaHV68 replication. These studies demonstrate an essential functional role for amino acids in the BH3 peptide binding groove of a viral Bcl-2 family member during chronic infection.

  12. The Impact of Adenosine Fast Induction of Myocardial Arrest during CABG on Myocardial Expression of Apoptosis-Regulating Genes Bax and Bcl-2

    Directory of Open Access Journals (Sweden)

    Ahmed Shalaby

    2009-01-01

    Full Text Available Background. We studied the effect of fast induction of cardiac arrest with denosine on myocardial bax and bcl-2 expression. Methods and Results. 40 elective CABG patients were allocated into two groups. The adenosine group (n=20 received 250 μg/kg adenosine into the aortic root followed by blood potassium cardioplegia. The control group received potassium cardioplegia in blood. Bcl-2 and bax were measured. Bax was reduced in the postoperative biopsies (1.38 versus 0.47, P=.002 in the control group. Bcl-2 showed a reducing tendency (0.14 versus 0.085, P=.07. After the adenosine treatment, the expression of both bax (0.52 versus 0.59, P=.4 and bcl-2 (0.104 versus 0.107, P=.4 remained unaltered after the operation. Conclusion. Open heart surgery is associated with rapid reduction in the expression of apoptosis regulating genes bax and bcl-2. Fast Adenosine induction abolished changes in their expression.

  13. Dynamin inhibitors induce caspase-mediated apoptosis following cytokinesis failure in human cancer cells and this is blocked by Bcl-2 overexpression

    Directory of Open Access Journals (Sweden)

    Braithwaite Antony W

    2011-06-01

    Full Text Available Abstract Background The aim of both classical (e.g. taxol and targeted anti-mitotic agents (e.g. Aurora kinase inhibitors is to disrupt the mitotic spindle. Such compounds are currently used in the clinic and/or are being tested in clinical trials for cancer treatment. We recently reported a new class of targeted anti-mitotic compounds that do not disrupt the mitotic spindle, but exclusively block completion of cytokinesis. This new class includes MiTMAB and OcTMAB (MiTMABs, which are potent inhibitors of the endocytic protein, dynamin. Like other anti-mitotics, MiTMABs are highly cytotoxic and possess anti-proliferative properties, which appear to be selective for cancer cells. The cellular response following cytokinesis failure and the mechanistic pathway involved is unknown. Results We show that MiTMABs induce cell death specifically following cytokinesis failure via the intrinsic apoptotic pathway. This involves cleavage of caspase-8, -9, -3 and PARP, DNA fragmentation and membrane blebbing. Apoptosis was blocked by the pan-caspase inhibitor, ZVAD, and in HeLa cells stably expressing the anti-apoptotic protein, Bcl-2. This resulted in an accumulation of polyploid cells. Caspases were not cleaved in MiTMAB-treated cells that did not enter mitosis. This is consistent with the model that apoptosis induced by MiTMABs occurs exclusively following cytokinesis failure. Cytokinesis failure induced by cytochalasin B also resulted in apoptosis, suggesting that disruption of this process is generally toxic to cells. Conclusion Collectively, these data indicate that MiTMAB-induced apoptosis is dependent on both polyploidization and specific intracellular signalling components. This suggests that dynamin and potentially other cytokinesis factors are novel targets for development of cancer therapeutics.

  14. Deletion of AU-rich elements within the Bcl2 3'UTR reduces protein expression and B cell survival in vivo.

    Directory of Open Access Journals (Sweden)

    Manuel D Díaz-Muñoz

    Full Text Available Post-transcriptional mRNA regulation by RNA binding proteins (RBPs associated with AU-rich elements (AREs present in the 3' untranslated region (3'UTR of specific mRNAs modulates transcript stability and translation in eukaryotic cells. Here we have functionally characterised the importance of the AREs present within the Bcl2 3'UTR in order to maintain Bcl2 expression. Gene targeting deletion of 300 nucleotides of the Bcl2 3'UTR rich in AREs diminishes Bcl2 mRNA stability and protein levels in primary B cells, decreasing cell lifespan. Generation of chimeric mice indicates that Bcl2-ARE∆/∆ B cells have an intrinsic competitive disadvantage compared to wild type cells. Biochemical assays and predictions using a bioinformatics approach show that several RBPs bind to the Bcl2 AREs, including AUF1 and HuR proteins. Altogether, association of RBPs to Bcl2 AREs contributes to Bcl2 protein expression by stabilizing Bcl2 mRNA and promotes B cell maintenance.

  15. Estimation of BCL-2 protein in carcinoma of the breast and its clinical correlation in locally advanced breast cancer

    Directory of Open Access Journals (Sweden)

    Aggarwal Himanshu

    2007-01-01

    Full Text Available The change in expression of apoptotic markers (Bcl-2 and Bax proteins brought about by various chemotherapeutic regimens is being used for its predictive value for assessing response to neoadjuvant chemotherapy (NACT in locally advanced breast carcinoma (LABC. Aims: (1 Estimation of Bcl 2 expression in LABC, (2 Any change in Bcl 2 expression following chemotherapy in LABC, (3 Any relation of Bcl 2 estimation to changes in size of tumor, nodal status, age, and menopausal status. Settings and Design: This was a prospective study of 120 cases of LABC. Materials and Methods: All cases were subjected to biopsy and the tissue was evaluated immunohistochemically for apoptotic marker Bcl-2 family protein. Three cycles of NACT were given at three-weekly intervals. Modified radical mastectomy was performed and the specimens were re-evaluated for any change in the Bcl-2 family protein. The clinical response and immunohistochemical response were correlated and compared. Statistical Analysis: Coefficient of correlation was calculated by Pearson correlation coefficient (P-value. Results: Clinical response, as measured by reduction in the tumor size, was observed in 81 (67.5% patients while immunohistochemical response was observed in 67 (55.8% patients. Correlation between immunohistochemical and clinical response was found to be statistically significant (P = 0.02. Nodal response was seen in 72 (60% patients. There were no patients in the N o group; 22 (53.7% of the N 1 patients were down-staged to N o , while 19 (46.3% remained N 1 . In patients with N 2 disease, 11 (13.9% were down-staged to N o status, 39 (49.4% were down-staged to N 1 status, and 29 (36.7% did not show any response. Immunohistochemical response was observed in 67 (55.8% patients. Correlation between immunohistochemical and nodal responses was also found to be statistically significant (P = 0.03. Conclusions: This significant positive correlation between clinical and immunohistochemical

  16. Gambogic acid induces mitochondria-dependent apoptosis by modulation of Bcl-2 and Bax in mantle cell lymphoma JeKo-1 cells

    Institute of Scientific and Technical Information of China (English)

    Jingyan Xu; Min Zhou; Jian Ouyang; Jing Wang; Qiguo Zhang; Yong Xu; Yueyi Xu

    2013-01-01

    Objective:To study the mechanisms in gambogic acid (GA)-induced JeKo-1 human Mantle Cell Lymphoma cell apoptosis in vitro.Methods:The proliferation of GA-treated JeKo-1 cells was measured by CCK-8 assay and Ki-67 immunocytochemical detection.Apoptosis,cell cycle and mitochondrial membrane potential were measured by flow cytometric analysis.Caspase-3,-8 and-9 were detected by colorimetric assay.Bcl-2 and Bax were analyzed by Western blotting.Results:GA inhibited cell growth in a time-and dose-dependent manner.GA induces apoptosis in JeKo-1 cells but not in normal bone marrow cells,which was involved in reducing the membrane potential of mitochondria,activating caspases-3,-8 and-9 and decreasing the ratio of Bcl-2 and Bax without cell cycle arresting.Conclusions:GA induced apoptosis in human MCL JeKo-1 cells by regulating Bcl-2/Bax and activating caspase-3,-8 and-9 via mitochondrial pathway without affecting cell cycle.

  17. Apoptosis and the activity of ceramide, Bax and Bcl-2 in the lungs of neonatal rats exposed to limited and prolonged hyperoxia

    OpenAIRE

    Bitar Fadi F; Nasser Michel; Panjarian Shoghag; Khayat Aline; Bitar Hala; Dbaibo Ghassan S; Husari Ahmad W; El-Sabban Marwan; Zaatari Ghazi; Mroueh Salman M

    2006-01-01

    Abstract Background The aim of the study is to examine the effect of limited and prolonged hyperoxia on neonatal rat lung. This is done by examining the morphologic changes of apoptosis, the expression of ceramide, an important mediator of apoptosis, the expression of inflammatory mediators represented by IL-1β and the expression of 2 proto-oncogenes that appear to modulate apoptosis (Bax and Bcl-2). Methods Newborn rats were placed in chambers containing room air or oxygen above 90% for 7 da...

  18. Small interfering RNA in silencing Bcl-2 expression and enhancing radiosensitivity of esophageal cancer cells

    International Nuclear Information System (INIS)

    Objective: To explore the effects of small interfering RNA (siRNA) specific to Bcl-2 gene on radiosensitivity of esophageal cancer cells. Methods: Bcl-2 gene siRNA ( Bcl-2 siRNA ) was induced into esophageal cancer EC9706 cells by lipofectamine. Bcl-2 protein expression and apoptosis of EC9706 cells were detected by flowcytometer. Clone forming assay was used to determine the inhibitory effects of X-ray radiation combined with Bcl-2 siRNA interference. Results: When Bcl-2 siRNA had been induced into EC9706 cells, Bcl-2 protein expression in EC9706 cells was inhibited, and cell apoptosis was increased. Bcl-2 protein expression rates of EC9706 cells induced with Bcl-2 siRNA1, A2, A3 (25.13% ±2.04%, 8.87% ± 3.34%, 30.55% ± 2.73%) were lower than the control group (84.28% ± 1.47%)(t =4.01, 3.043.64, P 0, Dq, and SF2 of combined treatment group were much lower than those of irradiation alone group . The sensitization enhancing ratio was 1.32 (ratio of D0 values). Conclusions: Bcl-2 gene siRNA could enhance the radiosensitivity of esophageal cancer EC9706 cells and may has a good future in clinical practice. (authors)

  19. Bcl-2-regulated cell death signalling in the prevention of autoimmunity

    OpenAIRE

    Tischner, D; Woess, C; Ottina, E; Villunger, A

    2010-01-01

    Cell death mediated through the intrinsic, Bcl-2-regulated mitochondrial apoptosis signalling pathway is critical for lymphocyte development and the establishment of central and maintenance of peripheral tolerance. Defects in Bcl-2-regulated cell death signalling have been reported to cause or correlate with autoimmunity in mice and men. This review focuses on the role of Bcl-2 family proteins implicated in the development of autoimmune disorders and their potential as targets for therapeutic...

  20. Altered Expression of Cellular Bcl-2 in the Progression of Hamster Cholangiocarcinogenesis

    OpenAIRE

    Byung-suk Jeon; Byung-IL Yoon

    2012-01-01

    Bcl-2 is an intracytoplasmic and membrane-associated apoptosis suppressor, and its overexpression is closely associated with survival of malignant tumors, in particular their aggressive behavior and poor prognosis. The role of Bcl-2 is, however, still controversial in cholangiocarcinogenesis because of the discrepancies in the expression of the protein. In the present study, alteration in the expression of Bcl-2 in cholangiocarcinogenesis was investigated by studying the immunoreactivities of...

  1. Effect of Bcl-2 rs956572 Polymorphism on Age-Related Gray Matter Volume Changes

    OpenAIRE

    Liu, Mu-En; Huang, Chu-Chung; Yang, Albert C.; Tu, Pei-Chi; Yeh, Heng-Liang; Hong, Chen-Jee; Chen, Jin-Fan; Liou, Ying-Jay; Lin, Ching-Po; Tsai, Shih-Jen

    2013-01-01

    The anti-apoptotic protein B-cell CLL/lymphoma 2 (Bcl-2) gene is a major regulator of neural plasticity and cellular resilience. Recently, the Bcl-2 rs956572 single nucleotide polymorphism was proposed to be a functional allelic variant that modulates cellular vulnerability to apoptosis. Our cross-sectional study investigated the genetic effect of this Bcl-2 polymorphism on age-related decreases in gray matter (GM) volume across the adult lifespan. Our sample comprised 330 healthy volunteers ...

  2. The role of the acidity of N-heteroaryl sulfonamides as inhibitors of bcl-2 family protein-protein interactions.

    Science.gov (United States)

    Touré, B Barry; Miller-Moslin, Karen; Yusuff, Naeem; Perez, Lawrence; Doré, Michael; Joud, Carol; Michael, Walter; DiPietro, Lucian; van der Plas, Simon; McEwan, Michael; Lenoir, Francois; Hoe, Madelene; Karki, Rajesh; Springer, Clayton; Sullivan, John; Levine, Kymberly; Fiorilla, Catherine; Xie, Xiaoling; Kulathila, Raviraj; Herlihy, Kara; Porter, Dale; Visser, Michael

    2013-02-14

    Overexpression of the antiapoptotic members of the Bcl-2 family of proteins is commonly associated with cancer cell survival and resistance to chemotherapeutics. Here, we describe the structure-based optimization of a series of N-heteroaryl sulfonamides that demonstrate potent mechanism-based cell death. The role of the acidic nature of the sulfonamide moiety as it relates to potency, solubility, and clearance is examined. This has led to the discovery of novel heterocyclic replacements for the acylsulfonamide core of ABT-737 and ABT-263. PMID:24900652

  3. The targeted inhibition of mitochondrial Hsp90 overcomes the apoptosis resistance conferred by Bcl-2 in Hep3B cells via necroptosis

    International Nuclear Information System (INIS)

    Previous studies have reported that a Gamitrinib variant containing triphenylphosphonium (G-TPP) binds to mitochondrial Hsp90 and rapidly inhibits its activity, thus inducing the apoptotic pathway in the cells. Accordingly, G-TPP shows a potential as a promising drug for the treatment of cancer. A cell can die from different types of cell death such as apoptosis, necrosis, necroptosis, and autophagic cell death. In this study, we further investigated the mechanisms and modes of cell death in the G-TPP-treated Hep3B and U937 cell lines. We discovered that G-TPP kills the U937 cells through the apoptotic pathway and the overexpression of Bcl-2 significantly inhibits U937 cell death to G-TPP. We further discovered that G-TPP kills the Hep3B cells by activating necroptosis in combination with the partial activation of caspase-dependent apoptosis. Importantly, G-TPP overcomes the apoptosis resistance conferred by Bcl-2 in Hep3B cells via necroptosis. We also observed that G-TPP induces compensatory autophagy in the Hep3B cell line. We further found that whereas there is a Bcl-2-Beclin 1 interaction in response to G-TPP, silencing the beclin 1 gene failed to block LC3-II accumulation in the Hep3B cells, indicating that G-TPP triggers Beclin 1-independent protective autophagy in Hep3B cells. Taken together, these data reveal that G-TPP induces cell death through a combination of death pathways, including necroptosis and apoptosis, and overcomes the apoptosis resistance conferred by Bcl-2 in Hep3B cells via necroptosis. These findings are important for the therapeutic exploitation of necroptosis as an alternative cell death program to bypass the resistance to apoptosis. Highlights: ► G-TPP binds to mitochondrial Hsp90. ► G-TPP induces apoptosis in U937 human leukemia cancer cells. ► G-TPP induces combination of death pathways in Hep3B cell. ► G-TPP overcomes the resistance conferred by Bcl-2 in Hep3B cells via necroptosis. ► G-TPP triggers Beclin 1-independent

  4. The targeted inhibition of mitochondrial Hsp90 overcomes the apoptosis resistance conferred by Bcl-2 in Hep3B cells via necroptosis

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Chunlan [Department of Anatomy and Cell Biology, Dong-A University College of Medicine and Mitochondria Hub Regulation Center, Busan, 602-714 (Korea, Republic of); Department of Physiology, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058 (China); Oh, Joon Seok; Yoo, Seung Hee; Lee, Jee Suk [Department of Anatomy and Cell Biology, Dong-A University College of Medicine and Mitochondria Hub Regulation Center, Busan, 602-714 (Korea, Republic of); Yoon, Young Geol [Department of Anatomy and Cell Biology, Dong-A University College of Medicine and Mitochondria Hub Regulation Center, Busan, 602-714 (Korea, Republic of); Department of Biomedical Science, Institute for Biomedical and Health Sciences, Jungwon University, Chungbuk, 367-805 (Korea, Republic of); Oh, Yoo Jin; Jang, Min Seok [Department of Anatomy and Cell Biology, Dong-A University College of Medicine and Mitochondria Hub Regulation Center, Busan, 602-714 (Korea, Republic of); Lee, Sang Yeob [Department of Rheumatology, Dong-A University College of Medicine, Busan, 602-714 (Korea, Republic of); Yang, Jun [Department of Toxicology, Hangzhou Normal University School of Public Health, Hangzhou, Zhejiang, 310036 China (China); Lee, Sang Hwa [Department of Microbiology and, Dong-A University College of Medicine, Busan, 602-714 (Korea, Republic of); Kim, Hye Young [Department of Anatomy and Cell Biology, Dong-A University College of Medicine and Mitochondria Hub Regulation Center, Busan, 602-714 (Korea, Republic of); Yoo, Young Hyun, E-mail: yhyoo@dau.ac.kr [Department of Anatomy and Cell Biology, Dong-A University College of Medicine and Mitochondria Hub Regulation Center, Busan, 602-714 (Korea, Republic of)

    2013-01-01

    Previous studies have reported that a Gamitrinib variant containing triphenylphosphonium (G-TPP) binds to mitochondrial Hsp90 and rapidly inhibits its activity, thus inducing the apoptotic pathway in the cells. Accordingly, G-TPP shows a potential as a promising drug for the treatment of cancer. A cell can die from different types of cell death such as apoptosis, necrosis, necroptosis, and autophagic cell death. In this study, we further investigated the mechanisms and modes of cell death in the G-TPP-treated Hep3B and U937 cell lines. We discovered that G-TPP kills the U937 cells through the apoptotic pathway and the overexpression of Bcl-2 significantly inhibits U937 cell death to G-TPP. We further discovered that G-TPP kills the Hep3B cells by activating necroptosis in combination with the partial activation of caspase-dependent apoptosis. Importantly, G-TPP overcomes the apoptosis resistance conferred by Bcl-2 in Hep3B cells via necroptosis. We also observed that G-TPP induces compensatory autophagy in the Hep3B cell line. We further found that whereas there is a Bcl-2-Beclin 1 interaction in response to G-TPP, silencing the beclin 1 gene failed to block LC3-II accumulation in the Hep3B cells, indicating that G-TPP triggers Beclin 1-independent protective autophagy in Hep3B cells. Taken together, these data reveal that G-TPP induces cell death through a combination of death pathways, including necroptosis and apoptosis, and overcomes the apoptosis resistance conferred by Bcl-2 in Hep3B cells via necroptosis. These findings are important for the therapeutic exploitation of necroptosis as an alternative cell death program to bypass the resistance to apoptosis. Highlights: ► G-TPP binds to mitochondrial Hsp90. ► G-TPP induces apoptosis in U937 human leukemia cancer cells. ► G-TPP induces combination of death pathways in Hep3B cell. ► G-TPP overcomes the resistance conferred by Bcl-2 in Hep3B cells via necroptosis. ► G-TPP triggers Beclin 1-independent

  5. Effect of Hypoxic Preconditioning on Neural Cell Apoptosis and Expression of Bcl-2 and Bax in Cerebral Ischemia-Reperfusion in Rats

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In order to investigate the protective effect of hypoxic preconditioning on the cerebral ischemia-reperfusion injury, the expression of Bcl-2 and Bax was detected by using immunohistochemical staining after 3 h cerebral ischemia followed by 1, 6, 12, 24 and 48 h reperfusion respectively in rats treated with or without hypoxic preconditioning before cerebral ischemia. In addition,the apoptosis of neural cells and the behavioral scores for neurological functions recovery were evaluated by TUNEL staining and "crawvling method", respectively. Compared with control group (cerebral ischemia-reperfusion without hypoxic preconditioning), the expression of Bcl-2 was significantly increased, but that of Bax decreased in the hypoxic preconditioning group (cerebral ischemiareperfusion with hypoxic preconditioning), both P<0. 05. The pre-treatment with hypoxic preconditioning could reduce the apoptosis of neural cells and promote the neurological function recovery as compared to control group. It was suggested that hypoxic preconditioning may have protective effects on the cerebral ischemia-reperfusion injury by inhibiting the apoptosis of neural cells, increase the expression of Bcl-2 and decrease the expression of Bax.

  6. Apoptosis, mitosis, bcl-2, bax, and bcl-x as predictors of tumor response in stage I and II follicular lymphoma

    International Nuclear Information System (INIS)

    Purpose: Levels of spontaneous apoptosis predict for tumor responsiveness to radiation and chemotherapy in various animal systems. Oncogenes belonging to the bcl-2 family have been found to govern apoptosis, and bcl-2 has been shown to convey multi-drug resistance in lymphoma in vitro. To investigate the potential role of apoptosis and oncogenes involved in apoptosis as a predictors of response in human tumors, a retrospective review was undertaken of patients with Stage I and II follicular lymphoma in whom long term results were recently reported. Materials and Methods: The H and E slides of the initial specimens of 91 patients were obtained. All slides were reviewed by one pathologist (WCP) and representative sections were chosen. Twenty-four patients were treated with regional radiotherapy, 57 patients with multiagent chemotherapy and regional radiotherapy, and 10 patients with multiagent chemotherapy alone. Apoptotic index (AI) and mitotic index (MI) were determined for each tumor by counting the number of apoptotic bodies and mitotic cells present in 500 cells (100 cells in each of 5 follicles). Paraffin-embedded tissue was obtained for 52 of the initial specimens, and bcl-2, bax, and bcl-x status was determined by immunohistochemistry for these cases. The above parameters were correlated with overall survival (OS) and freedom from progression (FFP). Follow-up for living patients ranged from 51 to 212 months with a median value of 114 months. Results: The AI and MI values were low, ranging from 0 - 5.2% and 0 - 1.0%, respectively. The median AI value was 0.4%, and 63 patients had a MI of 0%. Patients who were treated with combined chemotherapy and radiotherapy had a higher FFP when their tumors had spontaneous levels of apoptosis of 0 had an improved FFP (83% vs 27% 10-year FFP; p=0.05). Bcl-2, bax and bcl-x staining was positive for 41, 48, and 47 initial specimens, respectively. No correlation of bcl-2, bax or bcl-x staining with clinical outcome was found

  7. Active fragments from pro- and antiapoptotic BCL-2 proteins have distinct membrane behavior reflecting their functional divergence.

    Directory of Open Access Journals (Sweden)

    Yannis Guillemin

    Full Text Available BACKGROUND: The BCL-2 family of proteins includes pro- and antiapoptotic members acting by controlling the permeabilization of mitochondria. Although the association of these proteins with the outer mitochondrial membrane is crucial for their function, little is known about the characteristics of this interaction. METHODOLOGY/PRINCIPAL FINDINGS: Here, we followed a reductionist approach to clarify to what extent membrane-active regions of homologous BCL-2 family proteins contribute to their functional divergence. Using isolated mitochondria as well as model lipid Langmuir monolayers coupled with Brewster Angle Microscopy, we explored systematically and comparatively the membrane activity and membrane-peptide interactions of fragments derived from the central helical hairpin of BAX, BCL-xL and BID. The results show a connection between the differing abilities of the assayed peptide fragments to contact, insert, destabilize and porate membranes and the activity of their cognate proteins in programmed cell death. CONCLUSION/SIGNIFICANCE: BCL-2 family-derived pore-forming helices thus represent structurally analogous, but functionally dissimilar membrane domains.

  8. KSP inhibitor SB743921 inhibits growth and induces apoptosis of breast cancer cells by regulating p53, Bcl-2, and DTL.

    Science.gov (United States)

    Zhu, Li; Xiao, Fengjun; Yu, Yue; Wang, Hua; Fang, Min; Yang, Yuefeng; Sun, Huiyan; Wang, Lisheng; Sheng, Yuan

    2016-10-01

    Kinesin spindle protein (KSP) is a microtubule-associated motor protein that is specifically expressed by mitosis cells. It is highly expressed in various types of tumors including hematomalignances and solid tumors. Chemical KSP inhibition has become a novel strategy in the development of anticancer drugs. SB743921 is a selective inhibitor for KSP, which is a mitotic protein essential for cell-cycle progression. Although SB743921 has shown antitumor activities for several types of cancers and entered into clinical trials, its therapeutic effects on breast cancer and mechanisms have not been explored. In this study, we tested the antitumor activity of SB743921 in breast cancer cell lines and partly elucidated its mechanisms. KSP and denticleless E3 ubiquitin-protein ligase homolog (DTL) are overexpressed in breast cancer cells compared with no-cancer tissues. Chemical inhibition of KSP by SB743921 not only reduces proliferation but also induces cell-cycle arrest and leads to apoptosis in breast cancer cells. Treatment of MCF-7 and MDA-MB-231 breast cancer cell lines with SB743921 results in decreased ability of colony formation in culture. SB743921 treatment also causes a KSP accumulation in protein level that is associated with cell arrest. Furthermore, we showed that SB743921 treatment significantly reduces the expression of bcl-2 and cell cycle-related protein DTL, and upregulates p53 and caspase-3 in breast cancer cells. Taken together, these data indicated that SB743921 can be expected to be a novel treatment agent for breast cancers. PMID:27379929

  9. Multimodal Interaction with BCL-2 Family Proteins Underlies the Pro-Apoptotic Activity of PUMA BH3

    OpenAIRE

    Edwards, Amanda L.; Gavathiotis, Evripidis; LaBelle, James L.; Braun, Craig R.; Opoku-Nsiah, Kwadwo A.; Bird, Gregory H.; Walensky, Loren D.

    2013-01-01

    PUMA is a pro-apoptotic BCL-2 family member that drives the apoptotic response to a diversity of p53-dependent and independent cellular insults. Deciphering the spectrum of PUMA interactions that confer its context-dependent pro-apoptotic properties remains a high priority goal. Here, we report the synthesis of PUMA SAHBs, structurally-stabilized PUMA BH3 helices that, in addition to broadly targeting anti-apoptotic proteins, directly bind to BAX. NMR, photocrosslinking, and biochemical analy...

  10. Evaluation of Bax and Bcl-2 Proteins Expression in the Rat Hippocampus due to Childhood Febrile Seizure

    OpenAIRE

    SAEEDI BORUJENI, Mohammad Javad; Hami, Javad; Haghir, Hossein; Rastin, Maryam; Sazegar, Ghasem

    2016-01-01

    Objective Simple Febrile Seizure (SFS) is the most common seizure disorder in childhood, and is frequently described as inoffensive disorder. Nevertheless, there is evidence suggesting the association between neonatal febrile seizures and hippocampal abnormalities in adulthood. This study was conducted at evaluating the hippocampal expression of pro-apoptotic Bax and anti-apoptotic Bcl-2 proteins following SFS induction in rat neonates. Materials & Methods Febrile seizure was modeled by hyper...

  11. Peptide screening to knockdown Bcl-2's anti-apoptotic activity: implications in cancer treatment.

    Science.gov (United States)

    Raghav, Pawan Kumar; Verma, Yogesh Kumar; Gangenahalli, Gurudutta U

    2012-04-01

    Bcl-2 (B cell lymphoma-2) is an anti-apoptotic member of Bcl-2 family and its overexpression causes development of several types of cancer. The BH3 domain of pro-apoptotic and BH3-only proteins is capable of binding to Bcl-2 protein to induce apoptosis. This binding is the basis for the development of novel anticancer drug which would likely antagonize Bcl-2 overexpression. In this study we have identified BH3 domain of Bax (Bax BH3) as potentially the best Bcl-2 antagonist by performing docking of BH3 peptides (peptides representing BH3 domain of pro-apoptotic and BH3-only proteins) into the Bcl-2 hydrophobic groove formed by BH3, BH1 and BH2 domains (also referred as BH3 cleft). To predict the best small antagonist for Bcl-2, three groups of small peptides (pentapeptide, tetrapeptide and tripeptide) were designed and screened against Bcl-2 which revealed the structural importance of a set of residues playing a vital role in interaction with Bcl-2. The docking and scoring function identified KRIG and KRI as specific peptides among the screened small peptides responsible for Bcl-2 neutralization and would induce apoptosis. The applied pharmacokinetic and pharmacological filters to all small peptides signify that only IGD has drug-like properties and displayed good oral bioavailability. However, the obtained binding affinity of IGD to Bcl-2 was diminutive. Hence deprotonation, amidation, acetylation, benzoylation, benzylation, and addition of phenyl, deoxyglucose and glucose fragments were performed to increase the binding affinity and to prevent its rapid degradation. Benzoylated IGD tripeptide (IGD(bzo)) was observed to have increased binding affinity than IGD with acceptable pharmacokinetic filters. In addition, stability of Bcl-2/IGD(bzo) complex was validated by Molecular Dynamics (MD) simulations revealing improved binding energy, salt bridges and strong interaction energies. This study suggests a new molecule that inhibits Bcl-2 associated cancer

  12. Interaction of a putative BH3 domain of clusterin with anti-apoptotic Bcl-2 family proteins as revealed by NMR spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dong-Hwa; Ha, Ji-Hyang [Medical Proteomics Research Center, KRIBB, Daejeon 305-806 (Korea, Republic of); Kim, Yul [Department of Bio and Brain Engineering, KAIST, Daejeon 305-701 (Korea, Republic of); Bae, Kwang-Hee [Medical Proteomics Research Center, KRIBB, Daejeon 305-806 (Korea, Republic of); Park, Jae-Yong [Department of Physiology, Institute of Health Science, School of Medicine, Gyeongsang National University, Jinju, Gyeongnam 660-751 (Korea, Republic of); Choi, Wan Sung [Department of Anatomy and Neurobiology, Institute of Health Science, School of Medicine, Gyeongsang National University, Jinju, Gyeongnam 660-751 (Korea, Republic of); Yoon, Ho Sup [Division of Structural and Computational Biology, School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637511 (Singapore); Park, Sung Goo; Park, Byoung Chul [Medical Proteomics Research Center, KRIBB, Daejeon 305-806 (Korea, Republic of); Yi, Gwan-Su, E-mail: gsyi@kaist.ac.kr [Department of Bio and Brain Engineering, KAIST, Daejeon 305-701 (Korea, Republic of); Chi, Seung-Wook, E-mail: swchi@kribb.re.kr [Medical Proteomics Research Center, KRIBB, Daejeon 305-806 (Korea, Republic of)

    2011-05-20

    Highlights: {yields} Identification of a conserved BH3 motif in C-terminal coiled coil region of nCLU. {yields} The nCLU BH3 domain binds to BH3 peptide-binding grooves in both Bcl-X{sub L} and Bcl-2. {yields} A conserved binding mechanism of nCLU BH3 and the other pro-apoptotic BH3 peptides with Bcl-X{sub L}. {yields} The absolutely conserved Leu323 and Asp328 of nCLU BH3 domain are critical for binding to Bcl-X{sub L.} {yields} Molecular understanding of the pro-apoptotic function of nCLU as a novel BH3-only protein. -- Abstract: Clusterin (CLU) is a multifunctional glycoprotein that is overexpressed in prostate and breast cancers. Although CLU is known to be involved in the regulation of apoptosis and cell survival, the precise molecular mechanism underlying the pro-apoptotic function of nuclear CLU (nCLU) remains unclear. In this study, we identified a conserved BH3 motif in C-terminal coiled coil (CC2) region of nCLU by sequence analysis and characterized the molecular interaction of the putative nCLU BH3 domain with anti-apoptotic Bcl-2 family proteins by nuclear magnetic resonance (NMR) spectroscopy. The chemical shift perturbation data demonstrated that the nCLU BH3 domain binds to pro-apoptotic BH3 peptide-binding grooves in both Bcl-X{sub L} and Bcl-2. A structural model of the Bcl-X{sub L}/nCLU BH3 peptide complex reveals that the binding mode is remarkably similar to those of other Bcl-X{sub L}/BH3 peptide complexes. In addition, mutational analysis confirmed that Leu323 and Asp328 of nCLU BH3 domain, absolutely conserved in the BH3 motifs of BH3-only protein family, are critical for binding to Bcl-X{sub L}. Taken altogether, our results suggest a molecular basis for the pro-apoptotic function of nCLU by elucidating the residue specific interactions of the BH3 motif in nCLU with anti-apoptotic Bcl-2 family proteins.

  13. Interaction of a putative BH3 domain of clusterin with anti-apoptotic Bcl-2 family proteins as revealed by NMR spectroscopy

    International Nuclear Information System (INIS)

    Highlights: → Identification of a conserved BH3 motif in C-terminal coiled coil region of nCLU. → The nCLU BH3 domain binds to BH3 peptide-binding grooves in both Bcl-XL and Bcl-2. → A conserved binding mechanism of nCLU BH3 and the other pro-apoptotic BH3 peptides with Bcl-XL. → The absolutely conserved Leu323 and Asp328 of nCLU BH3 domain are critical for binding to Bcl-XL. → Molecular understanding of the pro-apoptotic function of nCLU as a novel BH3-only protein. -- Abstract: Clusterin (CLU) is a multifunctional glycoprotein that is overexpressed in prostate and breast cancers. Although CLU is known to be involved in the regulation of apoptosis and cell survival, the precise molecular mechanism underlying the pro-apoptotic function of nuclear CLU (nCLU) remains unclear. In this study, we identified a conserved BH3 motif in C-terminal coiled coil (CC2) region of nCLU by sequence analysis and characterized the molecular interaction of the putative nCLU BH3 domain with anti-apoptotic Bcl-2 family proteins by nuclear magnetic resonance (NMR) spectroscopy. The chemical shift perturbation data demonstrated that the nCLU BH3 domain binds to pro-apoptotic BH3 peptide-binding grooves in both Bcl-XL and Bcl-2. A structural model of the Bcl-XL/nCLU BH3 peptide complex reveals that the binding mode is remarkably similar to those of other Bcl-XL/BH3 peptide complexes. In addition, mutational analysis confirmed that Leu323 and Asp328 of nCLU BH3 domain, absolutely conserved in the BH3 motifs of BH3-only protein family, are critical for binding to Bcl-XL. Taken altogether, our results suggest a molecular basis for the pro-apoptotic function of nCLU by elucidating the residue specific interactions of the BH3 motif in nCLU with anti-apoptotic Bcl-2 family proteins.

  14. Development of bcl-2 mRNA repressor of apoptosis in human fetal central nervous system%人胎儿中枢神经系统凋亡抑制因子bcl-2mRNA的发育

    Institute of Scientific and Technical Information of China (English)

    李泽桂; 蔡文琴

    2003-01-01

    目的研究人胎儿中枢神经系统凋亡抑制因子 bcl-2 mRNA 的发育表达.方法用地高辛标记的bcl-2 cRNA 探针原位杂交组织化学技术,检测了12~39周胎儿中枢神经系统内bcl-2 mRNA的表达情况. 结果①在所检测的各脑区均有bcl-2 mRNA表达.第12周,有强阳性的bcl-2 mRNA出现在脊髓、延髓的运动神经元、大脑额叶的皮质板; 小脑和大脑室层的bcl-2 mRNA表达较弱.bcl-2 mRNA的水平一般是随胎龄的增长而下降,至第39周表达最弱.②bcl-2 mRNA主要在神经元表达.结论在人胎儿神经系统发育中表达的bcl-2可能与编程性细胞死亡有关.

  15. 中度低温体外循环后大鼠海马bcl-2和bax的表达与神经元凋亡%Hippocampal bcl-2 and bax expressions and neuronal apoptosis after moderate hypothermic cardiopulmonary extracorporeal circulation in rats

    Institute of Scientific and Technical Information of China (English)

    张挺杰

    2005-01-01

    BACKGROUND: Hippocampus injury is wildly believed to involve in neurocognitive dysfunction; the establishment of a rat model of cardiopulmonary bypass(CPB) allows us to investigate the mechanism of CPB-related hippocampus injury.OBJECTIVE: To investigate the effects of moderate hypothermic CPB with a hemodilution on hippocampal bcl-2 and bax gene expression and neuronal apoptosis in rats.DESIGN: A randomized group division study based on the experimental animals.SETTING: Department of anesthesiology in a university hospital.MATERIALS: Thirty Sprague-Dawley (SD) rats were randomly divided into two groups, CPB group and sham-CPB group with 15 rats in each group.METHODS: Total 15 rats of CPB group were subjected to 60-minute moderate hypothermic nonpulsatile CPB using a peristaltic pump and a membrane oxygenator. The CPB circuit was primed with approximately 20 mL 1:1crystaloid-colloid liquid, while another 15 rats of sham-CPB group underwent identical anesthetic and surgical procedures(including cannulation) except CPB itself. At 1 hour post-CPB, six rats in each group were decapitated, and hippocampi were removed, homogenized, and processed for apoptotic gene ( bcl-2 and bax) mRNAs detection. Reverse transcriptase polymerase chain reaction(RT-PCR) is used to detect expression of mRNA by comparing the PCR product of bcl-2 or bax to those of β-actin housekeeping gene. Immunohistochemistry is used to detect bcl-2 and bax protein expressions and terminal deoxynucleiotidyl transferase-mediated dUTP-biotion nick end labeling(TUNEL) staining method was used to detect neuronal apoptosis at 6 hours post-CPB ( n = 6 in each group) . The protein expression was quantitated as percentage of the positively stained area in the total stained. In addition, hippocampal neuronal ultrastructures were studied by electron microscopy at 6 hours post-CPB( n = 3 in each group).ronal apoptosis and ultrastructure changes between the two groups.RESULTS: At 1 hour post-CPB, the expressions of

  16. Inotodiol inhabits proliferation and induces apoptosis through modulating expression of cyclinE, p27, bcl-2, and bax in human cervical cancer HeLa cells.

    Science.gov (United States)

    Zhao, Li-Wei; Zhong, Xiu-Hong; Yang, Shu-Yan; Zhang, Yi-Zhong; Yang, Ning-Jiang

    2014-01-01

    Inonotus obliquus is a medicinal mushroom that has been used as an effective agent to treat various diseases such as diabetes, tuberculosis and cancer. Inotodiol, an included triterpenoid shows significant anti-tumor effect. However, the mechanisms have not been well documented. In this study, we aimed to explore the effect of inotodiol on proliferation and apoptosis in human cervical cancer HeLa cells and investigated the underlying molecular mechanisms. HeLa cells were treated with different concentrations of inotodiol. The MTT assay was used to evaluate cell proliferating ability, flow cytometry (FCM) was employed for cell cycle analysis and cell apoptosis, while expression of cyclinE, p27, bcl-2 and bax was detected by immunocytochemistry. Proliferation of HeLa cells was inhibited by inotodiolin a dose-dependent manner at 24h (r=0.9999, pInonotus obliquus inhibited the proliferation of HeLa cells and induced apoptosis in vitro. The mechanisms may be related to promoting apoptosis through increasing the expression of bax and cutting bcl-2 and affecting the cell cycle by down-regulation the expression of cyclin E and up-regulation of p27. The results further indicate the potential value of inotodiol for treatment of human cervical cancer. PMID:24815470

  17. Effect of Buspirone, Fluoxetine and 8-OH-DPAT on Striatal Expression of Bax, Caspase-3 and Bcl-2 Proteins in 6-Hydroxydopamine-Induced Hemi-Parkinsonian Rats

    OpenAIRE

    Hamdollah Sharifi; Alireza Nayebi; Safar Farajnia; Rasool Haddadi

    2015-01-01

    Purpose: The exact pathogenesis of sporadic parkinson’s disease (PD) is still unclear. Numerous evidences suggest involvement of apoptosis in the death of dopaminergic neurons. In this study we investigated the effect of sub-chronic administration of buspirone, fluoxetine and 8-hydroxy-2-[di-n-propylamino]tetralin (8-OH-DPAT) in 6-hydroxydopamine (6-OHDA)-lesioned rats and assayed striatal concentrations of apoptotic (Bax, Caspase3) and anti-apoptotic (Bcl-2) proteins. M...

  18. Garlic ((Allium sativum)) Fresh Juice Induces Apoptosis in Human Oral Squamous Cell Carcinoma: The Involvement of Caspase-3, Bax and Bcl-2.

    Science.gov (United States)

    Farhadi, Farrokh; Jahanpour, Salar; Hazem, Kameliya; Aghbali, Amirala; Baradran, Behzad; Vahid Pakdel, Seyyed Mahdi

    2015-01-01

    Background and aims. There is no report on the apoptotic impact of Allium sativum L.(Garlic) on the oral squamous cell carcinoma (KB); hence, this study was designed to survey the apoptotic effects of garlic fresh juice (GFJ) on the KB cells. Materials and methods. MTTassay (MicrocultureTetrazolium Assay) was carried out to evaluate the cytotoxicity of GFJ on KB cells. Furthermore, TUNEL(Terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling)and DNA fragmentation tests were performed to determine if GFJ is able to induce apoptosis in KB cells. Also a standard kit was used to assess caspase-3 activity in KB cells. Also western blotting was employed to evaluate the effect of GFJ on Bax:Bcl-2 ratio. Results. Significant cytotoxic effects were observed for the minimum used concentration (1μg/mL) as calculated to be 77.97±2.3% for 24 h and 818±3.1% for 36h of incubation (P < 0.001). Furthermore, TUNEL and DNA fragmentation tests corroborated the apoptosis inducing activity of GFJ. Consistently, after treating KB cells with GFJ(1μg/mL), caspase-3 activity and Bax:Bcl-2 ratio were raised by 7.3±0.6 and (P <0.001) folds, respectively. Conclusion. The results of this study advanced that GFJ induces apoptosis in the KB cells through increasing caspase-3 activity and Bax:Bcl2 ratio which could be attributed to its organo-sulfurcomponents. PMID:26889365

  19. Cyanide-induced death of dopaminergic cells is mediated by uncoupling protein-2 up-regulation and reduced Bcl-2 expression

    International Nuclear Information System (INIS)

    Cyanide is a potent inhibitor of mitochondrial oxidative metabolism and produces mitochondria-mediated death of dopaminergic neurons and sublethal intoxications that are associated with a Parkinson-like syndrome. Cyanide toxicity is enhanced when mitochondrial uncoupling is stimulated following up-regulation of uncoupling protein-2 (UCP-2). In this study, the role of a pro-survival protein, Bcl-2, in cyanide-mediated cell death was determined in a rat dopaminergic immortalized mesencephalic cell line (N27 cells). Following pharmacological up-regulation of UCP-2 by treatment with Wy14,643, cyanide reduced cellular Bcl-2 expression by increasing proteasomal degradation of the protein. The increased turnover of Bcl-2 was mediated by an increase of oxidative stress following UCP-2 up-regulation. The oxidative stress involved depletion of mitochondrial glutathione (mtGSH) and increased H2O2 generation. Repletion of mtGSH by loading cells with glutathione ethyl ester reduced H2O2 generation and in turn blocked the cyanide-induced decrease of Bcl-2. To determine if UCP-2 mediated the response, RNAi knock down was conducted. The RNAi decreased cyanide-induced depletion of mtGSH, reduced H2O2 accumulation, and inhibited down-regulation of Bcl-2, thus blocking cell death. To confirm the role of Bcl-2 down-regulation in the cell death, it was shown that over-expression of Bcl-2 by cDNA transfection attenuated the enhancement of cyanide toxicity after UCP-2 up-regulation. It was concluded that UCP-2 up-regulation sensitizes cells to cyanide by increasing cellular oxidative stress, leading to an increase of Bcl-2 degradation. Then the reduced Bcl-2 levels sensitize the cells to cyanide-mediated cell death.

  20. Cell Cycle Arrest and Apoptosis Induction via Modulation of Mitochondrial Integrity by Bcl-2 Family Members and Caspase Dependence in Dracaena cinnabari-Treated H400 Human Oral Squamous Cell Carcinoma

    Science.gov (United States)

    Alabsi, Aied M.; Lim, Kai Li; Paterson, Ian C.; Ali-Saeed, Rola; Muharram, Bushra A.

    2016-01-01

    Dracaena cinnabari Balf.f. is a red resin endemic to Socotra Island, Yemen. Although there have been several reports on its therapeutic properties, information on its cytotoxicity and anticancer effects is very limited. This study utilized a bioassay-guided fractionation approach to determine the cytotoxic and apoptosis-inducing effects of D. cinnabari on human oral squamous cell carcinoma (OSCC). The cytotoxic effects of D. cinnabari crude extract were observed in a panel of OSCC cell lines and were most pronounced in H400. Only fractions DCc and DCd were active on H400 cells; subfractions DCc15 and DCd16 exhibited the greatest cytotoxicity against H400 cells and D. cinnabari inhibited cells proliferation in a time-dependent manner. This was achieved primarily via apoptosis where externalization of phospholipid phosphatidylserine was observed using DAPI/Annexin V fluorescence double staining mechanism studied through mitochondrial membrane potential assay cytochrome c enzyme-linked immunosorbent and caspases activities revealed depolarization of mitochondrial membrane potential (MMP) and significant activation of caspases 9 and 3/7, concomitant with S phase arrest. Apoptotic proteins array suggested that MMP was regulated by Bcl-2 proteins family as results demonstrated an upregulation of Bax, Bad, and Bid as well as downregulation of Bcl-2. Hence, D. cinnabari has the potential to be developed as an anticancer agent.

  1. BCL-2 family protein, BAD is down-regulated in breast cancer and inhibits cell invasion

    International Nuclear Information System (INIS)

    We have previously demonstrated that the anti-apoptotic protein BAD is expressed in normal human breast tissue and shown that BAD inhibits expression of cyclin D1 to delay cell-cycle progression in breast cancer cells. Herein, expression of proteins in breast tissues was studied by immunohistochemistry and results were analyzed statistically to obtain semi-quantitative data. Biochemical and functional changes in BAD-overexpressing MCF7 breast cancer cells were evaluated using PCR, reporter assays, western blotting, ELISA and extracellular matrix invasion assays. Compared to normal tissues, Grade II breast cancers expressed low total/phosphorylated forms of BAD in both cytoplasmic and nuclear compartments. BAD overexpression decreased the expression of β-catenin, Sp1, and phosphorylation of STATs. BAD inhibited Ras/MEK/ERK and JNK signaling pathways, without affecting the p38 signaling pathway. Expression of the metastasis-related proteins, MMP10, VEGF, SNAIL, CXCR4, E-cadherin and TlMP2 was regulated by BAD with concomitant inhibition of extracellular matrix invasion. Inhibition of BAD by siRNA increased invasion and Akt/p-Akt levels. Clinical data and the results herein suggest that in addition to the effect on apoptosis, BAD conveys anti-metastatic effects and is a valuable prognostic marker in breast cancer. - Highlights: • BAD and p-BAD expressions are decreased in breast cancer compared with normal breast tissue. • BAD impedes breast cancer invasion and migration. • BAD inhibits the EMT and transcription factors that promote cancer cell migration. • Invasion and migration functions of BAD are distinct from the BAD's role in apoptosis

  2. BCL-2 family protein, BAD is down-regulated in breast cancer and inhibits cell invasion

    Energy Technology Data Exchange (ETDEWEB)

    Cekanova, Maria, E-mail: mcekanov@utk.edu [Department of Small Animal Clinical Sciences, College of Veterinary Medicine, The University of Tennessee, Knoxville, TN (United States); Fernando, Romaine I. [Department of Obstetrics and Gynecology, Graduate School of Medicine, Medical Center, The University of Tennessee, Knoxville, TN (United States); Siriwardhana, Nalin [Department of Animal Science, The University of Tennessee, Knoxville, TN (United States); Sukhthankar, Mugdha [Department of Biomedical and Diagnostics Sciences, College of Veterinary Medicine, The University of Tennessee, Knoxville, TN (United States); Parra, Columba de la [Department of Biochemistry, School of Medicine, University of Puerto Rico, Medical Sciences Campus, San Juan, PR (United States); Woraratphoka, Jirayus [Department of Obstetrics and Gynecology, Graduate School of Medicine, Medical Center, The University of Tennessee, Knoxville, TN (United States); Malone, Christine [Laboratory of Molecular Carcinogenesis, National Institute of Environmental Health Sciences, Research Triangle Park, NC (United States); Ström, Anders [Center for Nuclear Receptors and Cell Signaling, Department of Biology and Biochemistry, University of Houston, Houston, TX (United States); Baek, Seung J. [Department of Biomedical and Diagnostics Sciences, College of Veterinary Medicine, The University of Tennessee, Knoxville, TN (United States); Wade, Paul A. [Laboratory of Molecular Carcinogenesis, National Institute of Environmental Health Sciences, Research Triangle Park, NC (United States); Saxton, Arnold M. [Department of Animal Science, The University of Tennessee, Knoxville, TN (United States); Donnell, Robert M. [Department of Biomedical and Diagnostics Sciences, College of Veterinary Medicine, The University of Tennessee, Knoxville, TN (United States); Pestell, Richard G. [Department of Cancer Biology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA (United States); and others

    2015-02-01

    We have previously demonstrated that the anti-apoptotic protein BAD is expressed in normal human breast tissue and shown that BAD inhibits expression of cyclin D1 to delay cell-cycle progression in breast cancer cells. Herein, expression of proteins in breast tissues was studied by immunohistochemistry and results were analyzed statistically to obtain semi-quantitative data. Biochemical and functional changes in BAD-overexpressing MCF7 breast cancer cells were evaluated using PCR, reporter assays, western blotting, ELISA and extracellular matrix invasion assays. Compared to normal tissues, Grade II breast cancers expressed low total/phosphorylated forms of BAD in both cytoplasmic and nuclear compartments. BAD overexpression decreased the expression of β-catenin, Sp1, and phosphorylation of STATs. BAD inhibited Ras/MEK/ERK and JNK signaling pathways, without affecting the p38 signaling pathway. Expression of the metastasis-related proteins, MMP10, VEGF, SNAIL, CXCR4, E-cadherin and TlMP2 was regulated by BAD with concomitant inhibition of extracellular matrix invasion. Inhibition of BAD by siRNA increased invasion and Akt/p-Akt levels. Clinical data and the results herein suggest that in addition to the effect on apoptosis, BAD conveys anti-metastatic effects and is a valuable prognostic marker in breast cancer. - Highlights: • BAD and p-BAD expressions are decreased in breast cancer compared with normal breast tissue. • BAD impedes breast cancer invasion and migration. • BAD inhibits the EMT and transcription factors that promote cancer cell migration. • Invasion and migration functions of BAD are distinct from the BAD's role in apoptosis.

  3. Hypoxia-induced Bcl-2 expression in endothelial cells via p38 MAPK pathway

    International Nuclear Information System (INIS)

    Angiogenesis and apoptosis are reciprocal processes in endothelial cells. Bcl-2, an anti-apoptotic protein, has been found to have angiogenic activities. The purpose of this study was to determine the role of Bcl-2 in hypoxia-induced angiogenesis in endothelial cells and to investigate the underlying mechanisms. Human aortic endothelial cells (HAECs) were exposed to hypoxia followed by reoxygenation. Myocardial ischemia and reperfusion mouse model was used and Bcl-2 expression was assessed. Bcl-2 expression increased in a time-dependent manner in response to hypoxia from 2 to 72 h. Peak expression occurred at 12 h (3- to 4-fold, p < 0.05). p38 inhibitor (SB203580) blocked hypoxia-induced Bcl-2 expression, whereas PKC, ERK1/2 and PI3K inhibitors did not. Knockdown of Bcl-2 resulted in decreased HAECs' proliferation and migration. Over-expression of Bcl-2 increased HAECs' tubule formation, whereas knockdown of Bcl-2 inhibited this process. In this model of myocardial ischemia and reperfusion, Bcl-2 expression was increased and was associated with increased p38 MAPK activation. Our results showed that hypoxia induces Bcl-2 expression in HAECs via p38 MAPK pathway.

  4. Deregulated expression of A1, Bcl-2, Bcl-xL, and Mcl-1 antiapoptotic proteins and Bid, Bad, and Bax proapoptotic genes in polycythemia vera patients

    Directory of Open Access Journals (Sweden)

    Elainy Patricia Lino Gasparotto

    2011-12-01

    Full Text Available Apoptosis deregulation might have a role in the pathophysiology of polycythemia vera (PV. This study evaluated Bcl-2 molecule expression in CD34+ cells and leukocytes in 12 PV patients. Gene expression was investigated by real time PCR using SybrGreen Quantitect kit and protein expression was evaluated by western-blotting. JAK2 V617F mutation was detected according to Baxter et al (2005. CD34+ cells from PV patients presented higher levels of A1 and Mcl-1 expression (median: 22.6 and 5.2, respectively in comparison with controls (0.9 and 0.5, p=0.004 and p=0.020; while Bcl-2 and Bcl-xL expression decreased in PV patients (0.18 and 1.19 compared with controls (1.39 and 2.01, p=0.006 and p=0.020. CD34+ cells in PV patients showed an elevated Bid expression (14.4 in comparison with healthy subjects (1.0; p=0.002. Patients' leukocytes showed an A1 augmentation (7.41, p=0.001 and a reduced expression of Bax (0.19; p=0.040 and Bad (0.2; p=0.030. There was no correlation between JAK2 V617F allele burden and molecular expression. PV patients showed alterations in Bcl-2 members' expression, which may interfere with control of apoptotic machinery and contribute to disease pathogenesis.A desregulação da apoptose parece participar da fisiopatologia da policitemia vera (PV. Este estudo avaliou a expressão das moléculas da família Bcl-2 em células hematopoéticas CD34 + e leucócitos de 12 pacientes com PV. Foram realizados: a quantificação da expressão gênica por PCR em tempo real utilizando kit Sybrgreen Quantitect, avaliação da expressão de proteínas por western-blot e detecção da mutação JAK2 V617F segundo Baxter et al. (2005. Células CD34 + dos pacientes com PV apresentaram maior expressão de A1 e Mcl-1 (mediana: 22,6 e 5,2, respectivamente em comparação com controles (0,9 e 0,5, p = 0,004 e p = 0,020 e expressão de Bcl-2 e Bcl-xL diminuída nestes pacientes (0,18 e 1,19 em relação aos controles (1,39 e 2,01, p = 0,006 e p = 0

  5. Ionizing radiation enhances therapeutic activity of mda-7/IL-24: overcoming radiation- and mda-7/IL-24-resistance in prostate cancer cells overexpressing the antiapoptotic proteins bcl-xL or bcl-2.

    Science.gov (United States)

    Su, Z-Z; Lebedeva, I V; Sarkar, D; Emdad, L; Gupta, P; Kitada, S; Dent, P; Reed, J C; Fisher, P B

    2006-04-13

    Subtraction hybridization applied to terminally differentiating human melanoma cells identified mda-7/IL-24, a cytokine belonging to the IL-10 gene superfamily. Adenoviral-mediated delivery of mda-7/IL-24 (Ad.mda-7) provokes apoptosis selectively in a wide spectrum of cancers in vitro in cell culture, in vivo in human tumor xenograft animal models and in patients with advanced carcinomas and melanomas. In human prostate cancer cells, a role for mitochondrial dysfunction and induction of reactive oxygen species in the apoptotic process has been established. Ectopic overexpression of bcl-xL and bcl-2 prevents these changes including apoptosis induction in prostate tumor cells by Ad.mda-7. We now document that this resistance to apoptosis can be reversed by treating bcl-2 family overexpressing prostate tumor cells with ionizing radiation in combination with Ad.mda-7 or purified GST-MDA-7 protein. Additionally, radiation augments apoptosis induction by mda-7/IL-24 in parental and neomycin-resistant prostate tumor cells. Radiosensitization to mda-7/IL-24 is dependent on JNK signaling, as treatment with the JNK 1/2/3 inhibitor SP600125 abolishes this effect. Considering that elevated expression of bcl-xL and bcl-2 are frequent events in prostate cancer development and progression, the present studies support the use of ionizing radiation in combination with mda-7/IL-24 as a means of augmenting the therapeutic benefit of this gene in prostate cancer, particularly in the context of tumors displaying resistance to radiation therapy owing to bcl-2 family member overexpression. PMID:16331261

  6. Bcl-2 Inhibitors: Targeting Mitochondrial Apoptotic Pathways in Cancer Therapy

    OpenAIRE

    Kang, Min H.; Reynolds, C. Patrick

    2009-01-01

    Defects in apoptotic pathways can promote cancer cell survival and also confer resistance to antineoplastic drugs. One pathway being targeted for antineoplastic therapy is the anti-apoptotic B-cell lymphoma-2 (Bcl-2) family of proteins (Bcl-2, Bcl-XL, Bcl-w, Mcl-1, Bfl1/A-1, and Bcl-B) that bind to and inactivate BH3-domain pro-apoptotic proteins. Signals transmitted by cellular damage (including antineoplastic drugs) or cytokine deprivation can initiate apoptosis via the intrinsic apoptotic ...

  7. Superoxide-mediated proteasomal degradation of Bcl-2 determines cell susceptibility to Cr(VI)-induced apoptosis

    OpenAIRE

    Azad, Neelam; Iyer, Anand Krishnan V.; Manosroi, Aranya; Wang, Liying; Rojanasakul, Yon

    2008-01-01

    Hexavalent chromium [Cr(VI)] compounds are redox cycling environmental carcinogens that induce apoptosis as the primary mode of cell death. Defects in apoptosis regulatory mechanisms contribute to carcinogenesis induced by Cr(VI). Activation of apoptosis signaling pathways is tightly linked with the generation of reactive oxygen species (ROS). Likewise, ROS have been implicated in the regulation of Cr(VI)-induced apoptosis and carcinogenicity; however, its role in Cr(VI)-induced apoptosis and...

  8. [Impact of the antioxidant Phenozan and low dose radiation on the level of p53 and BCL-2 proteins of mice different lines].

    Science.gov (United States)

    Mil', E M; Albantova, A A; Burlakova, E B

    2010-01-01

    The influence of the antioxidant Phenozan and 1.2 cGy gamma-radiation on the level of apoptotic proteins was determined for normal mice of F1 (CBA x C57BL) and leucosis AKR mice that are more sensitive to the irradiation. The constitutional level of p53 proteins in serum leucosis AKR mice was higher, than those in F1 (CBA x C57BL) mice, possible from accumulation of mutant p53 protein and viral infection of AKR mice. It was determined that injection of Phenozan in 10(-14) mol/kg and in 10(-4) mol/kg led to rising a p53 protein and bcl-2 protein level in serum and spleen in these line of mice, and lowering the number of double-strand breaks DNA spleen shown earlier. Common action Phenozan and 1.2 cGy gamma-radiation led to higher rising of p53 protein level than Phenozan only in F1 (CBA x C57BL) mice, stimulate possibly different pathway of p53 regulation. We assume that Phenozan can activate the reparation processes but not the processes of apoptosis in the cell and has a radioprotective properties. PMID:20297682

  9. Niclosamide, an anti-helminthic molecule, downregulates the retroviral oncoprotein Tax and pro-survival Bcl-2 proteins in HTLV-1-transformed T lymphocytes

    Energy Technology Data Exchange (ETDEWEB)

    Xiang, Di [Penn State Hershey Cancer Institute, Penn State University College of Medicine, Hershey, PA 17033 (United States); Yuan, Yunsheng [Penn State Hershey Cancer Institute, Penn State University College of Medicine, Hershey, PA 17033 (United States); Engineering Research Center of Cell and Therapeutic Antibody, Ministry of Education, School of Pharmacy, Shanghai Jiao Tong University, Shanghai (China); Chen, Li [Pharmacy College, Fujian University of Traditional Chinese Medicine, Fuzhou (China); Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD 21201 (United States); Liu, Xin; Belani, Chandra [Penn State Hershey Cancer Institute, Penn State University College of Medicine, Hershey, PA 17033 (United States); Cheng, Hua, E-mail: hcheng@ihv.umaryland.edu [Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD 21201 (United States); Marlene and Stewart Greenebaum Cancer Center, University of Maryland School of Medicine, Baltimore, MD 21201 (United States); Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201 (United States); Department Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD 21201 (United States)

    2015-08-14

    Adult T cell leukemia and lymphoma (ATL) is a highly aggressive form of hematological malignancy and is caused by chronic infection of human T cell leukemia virus type 1 (HTLV-1). The viral genome encodes an oncogenic protein, Tax, which plays a key role in transactivating viral gene transcription and in deregulating cellular oncogenic signaling to promote survival, proliferation and transformation of virally infected T cells. Hence, Tax is a desirable therapeutic target, particularly at early stage of HTLV-1-mediated oncogenesis. We here show that niclosamide, an anti-helminthic molecule, induced apoptosis of HTLV-1-transformed T cells. Niclosamide facilitated degradation of the Tax protein in proteasome. Consistent with niclosamide-mediated Tax degradation, this compound inhibited activities of MAPK/ERK1/2 and IκB kinases. In addition, niclosamide downregulated Stat3 and pro-survival Bcl-2 family members such as Mcl-1 and repressed the viral gene transcription of HTLV-1 through induction of Tax degradation. Since Tax, Stat3 and Mcl-1 are crucial molecules for promoting survival and growth of HTLV-1-transformed T cells, our findings demonstrate a novel mechanism of niclosamide in inducing Tax degradation and downregulating various cellular pro-survival molecules, thereby promoting apoptosis of HTLV-1-associated leukemia cells. - Highlights: • Niclosamide is a promising therapeutic candidate for adult T cell leukemia. • Niclosamide employs a novel mechanism through proteasomal degradation of Tax. • Niclosamide downregulates certain cellular pro-survival molecules.

  10. Niclosamide, an anti-helminthic molecule, downregulates the retroviral oncoprotein Tax and pro-survival Bcl-2 proteins in HTLV-1-transformed T lymphocytes

    International Nuclear Information System (INIS)

    Adult T cell leukemia and lymphoma (ATL) is a highly aggressive form of hematological malignancy and is caused by chronic infection of human T cell leukemia virus type 1 (HTLV-1). The viral genome encodes an oncogenic protein, Tax, which plays a key role in transactivating viral gene transcription and in deregulating cellular oncogenic signaling to promote survival, proliferation and transformation of virally infected T cells. Hence, Tax is a desirable therapeutic target, particularly at early stage of HTLV-1-mediated oncogenesis. We here show that niclosamide, an anti-helminthic molecule, induced apoptosis of HTLV-1-transformed T cells. Niclosamide facilitated degradation of the Tax protein in proteasome. Consistent with niclosamide-mediated Tax degradation, this compound inhibited activities of MAPK/ERK1/2 and IκB kinases. In addition, niclosamide downregulated Stat3 and pro-survival Bcl-2 family members such as Mcl-1 and repressed the viral gene transcription of HTLV-1 through induction of Tax degradation. Since Tax, Stat3 and Mcl-1 are crucial molecules for promoting survival and growth of HTLV-1-transformed T cells, our findings demonstrate a novel mechanism of niclosamide in inducing Tax degradation and downregulating various cellular pro-survival molecules, thereby promoting apoptosis of HTLV-1-associated leukemia cells. - Highlights: • Niclosamide is a promising therapeutic candidate for adult T cell leukemia. • Niclosamide employs a novel mechanism through proteasomal degradation of Tax. • Niclosamide downregulates certain cellular pro-survival molecules

  11. Predictive value of bcl-2 immunoreactivity in prostate cancer patients treated with radiotherapy

    International Nuclear Information System (INIS)

    Background and purpose: Recent experimental evidence suggests that overexpression of bcl-2, a protein functioning by blocking apoptosis, may influence the treatment outcome in human tumours, including prostate cancer. To test the clinical implications of this hypothesis, tumours from patients with prostate cancer treated with external beam radiotherapy were investigated for bcl-2 immunoreactivity (IR) and correlated with prognosis and treatment outcome. Materials and methods: Bcl-2 IR was evaluated in archival tumour specimens obtained through transurethral resection from 42 patients with localized prostate cancer (T0-T4, N0 and M0). Bcl-2 IR expression was related to stage, grade and cancer-specific survival. Specimens were obtained prior to administrating routine radiotherapy for all patients. Results: Bcl-2 IR was present in 19/42 (45%) tumours. The bcl-2-positive patients had a significantly longer cancer-specific survival than the bcl-2-negative patients (10.3 versus 3.4 years, P<0.04). At follow-up (7-19 years), nine patients were still alive, 26 patients had died of prostate cancer and seven patients had died of other causes. Conclusions: This study indicates that pre-treatment bcl-2 overexpression is related to a favourable outcome in prostate cancer treated with radiotherapy. Low bcl-2 along with a high stage may be a predictor of poor prognosis and these patients might benefit from additional treatment. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  12. BCL-2 family proteins as 5-Azacytidine-sensitizing targets and determinants of response in myeloid malignancies

    OpenAIRE

    Bogenberger, J M; Kornblau, S. M.; Pierceall, W E; Lena, R.; Chow, D.; Shi, C-X; Mantei, J; Ahmann, G; Gonzales, I M; A. Choudhary; R. Valdez; Camoriano, J; Fauble, V; Tiedemann, R E; Qiu, Y H

    2014-01-01

    Synergistic molecular vulnerabilities enhancing hypomethylating agents in myeloid malignancies have remained elusive. RNA-interference drug modifier screens identified antiapoptotic BCL-2 family members as potent 5-Azacytidine-sensitizing targets. In further dissecting BCL-XL, BCL-2 and MCL-1 contribution to 5-Azacytidine activity, siRNA silencing of BCL-XL and MCL-1, but not BCL-2, exhibited variable synergy with 5-Azacytidine in vitro. The BCL-XL, BCL-2 and BCL-w inhibitor ABT-737 sensitize...

  13. Cannabinoid Receptor Type 2 Agonist Attenuates Apoptosis by Activation of Phosphorylated CREB-Bcl-2 Pathway After Subarachnoid Hemorrhage in Rats

    OpenAIRE

    Fujii, Mutsumi; Sherchan, Prativa; Soejima, Yoshiteru; Hasegawa, Yu; Flores, Jerry; Doycheva, Desislava; Zhang, John H.

    2014-01-01

    Early brain injury (EBI) which comprises of vasogenic edema and apoptotic cell death is an important component of subarachnoid hemorrhage (SAH) pathophysiology. This study evaluated whether Cannabinoid receptor type 2 (CB2R) agonist, JWH133, attenuates EBI after SAH and whether CB2R stimulation reduces pro-apoptotic caspase-3 via up-regulation of cAMP response element-binding protein (CREB)-Bcl-2 signaling pathway. Male Sprague Dawley rats (n=123) were subjected to SAH by endovascular perfora...

  14. Targeting BCL-2 to enhance vulnerability to therapy in estrogen receptor-positive breast cancer.

    Science.gov (United States)

    Merino, D; Lok, S W; Visvader, J E; Lindeman, G J

    2016-04-14

    The last three decades have seen significant progress in our understanding of the role of the pro-survival protein BCL-2 and its family members in apoptosis and cancer. BCL-2 and other pro-survival family members including Mcl-1 and BCL-XL have been shown to have a key role in keeping pro-apoptotic 'effector' proteins BAK and BAX in check. They also neutralize a group of 'sensor' proteins (such as BIM), which are triggered by cytotoxic stimuli such as chemotherapy. BCL-2 proteins therefore have a central role as guardians against apoptosis, helping cancer cells to evade cell death. More recently, an increasing number of BH3 mimetics, which bind and neutralize BCL-2 and/or its pro-survival relatives, have been developed. The utility of targeting BCL-2 in hematological malignancies has become evident in early-phase studies, with remarkable clinical responses seen in heavily pretreated patients. As BCL-2 is overexpressed in ~75% of breast cancer, there has been growing interest in determining whether this new class of drug could show similar promise in breast cancer. This review summarizes our current understanding of the role of BCL-2 and its family members in mammary gland development and breast cancer, recent progress in the development of new BH3 mimetics as well as their potential for targeting estrogen receptor-positive breast cancer. PMID:26257067

  15. Expression of bcl-2 in the Epithelial Lining of Odontogenic Keratocysts

    Directory of Open Access Journals (Sweden)

    Gh. Jahanshahi

    2006-03-01

    Full Text Available Statement of Problem: The aggressive nature and high recurrence rate of Odontogenic Keratocysts (OKCs may be due to unknown factors inherent in the epithelium or because of enzymatic activity in the fibrous wall. Bcl-2 protein is characterized by its ability to inhibit apoptosis.Purpose: The aim of the present study was to analyze the expression of bcl-2 protein in OKCs and to compare it with the more common radicular and dentigerous cysts. The possible relationship between inflammation and bcl-2 expression was also investigated.Materials and Methods: Formalin fixed paraffin-embedded tissue sections of 20 OKCs, 20 radicular and 20 dentigerous cysts were immunohistochemically analyzed for immunoreactivity of the bcl-2 protein.Results: Bcl-2 expression was observed in 19 OKCs (95%, one radicular cyst (5%and one dentigerous cyst (5%. There was no statistically significant relationship between inflammation and the number of bcl-2 positive cells. Immunoreactivity was mainly noted in the basal or basal/supra basal layers.Conclusion: Considering the fact that bcl-2 over expression may lead to increased survival of epithelial cells, present study may demonstrate a possible relationship between the aggressive nature of OKC and the intrinsic growth potential of its lining epithelium. Furthermore a basal/supra basal distribution of bcl-2 positive cells was seen in some odontogenic keratocysts which may have a significant impact on the behavior of this cyst.

  16. Microwave-Assisted Synthesis of Arene Ru(II Complexes Induce Tumor Cell Apoptosis Through Selectively Binding and Stabilizing bcl-2 G-Quadruplex DNA

    Directory of Open Access Journals (Sweden)

    Yanhua Chen

    2016-05-01

    Full Text Available A series of arene Ru(II complexes coordinated with phenanthroimidazole derivatives, [(η6-C6H6Ru(lCl]Cl(1b L = p-ClPIP = 2-(4-Chlorophenylimidazole[4,5f] 1,10-phenanthroline; 2b L = m-ClPIP = 2-(3-Chlorophenylimidazole[4,5f] 1,10-phenanthroline; 3b L = p-NPIP = 2-(4-Nitrophenylimidazole[4,5f] 1,10-phenanthroline; 4b L = m-NPIP = 2-(3-Nitrophenyl imidazole [4,5f] 1,10-phenanthroline were synthesized in yields of 89.9%–92.7% under conditions of microwave irradiation heating for 30 min to liberate four arene Ru(II complexes (1b, 2b, 3b, 4b. The anti-tumor activity of 1b against various tumor cells was evaluated by MTT assay. The results indicated that this complex blocked the growth of human lung adenocarcinoma A549 cells with an IC50 of 16.59 μM. Flow cytometric analysis showed that apoptosis of A549 cells was observed following treatment with 1b. Furthermore, the in vitro DNA-binding behaviors that were confirmed by spectroscopy indicated that 1b could selectively bind and stabilize bcl-2 G-quadruplex DNA to induce apoptosis of A549 cells. Therefore, the synthesized 1b has impressive bcl-2 G-quadruplex DNA-binding and stabilizing activities with potential applications in cancer chemotherapy.

  17. NEW EMBO MEMBER’S REVIEW: Viral and bacterial proteins regulating apoptosis at the mitochondrial level

    OpenAIRE

    Boya, Patricia; Roques, Bernard,; Kroemer, Guido

    2001-01-01

    Mitochondrial membrane permeabilization (MMP) is a critical step of several apoptotic pathways. Some infectious intracellular pathogens can regulate (induce or inhibit) apoptosis of their host cells at the mitochondrial level, by targeting proteins to mitochondrial membranes that either induce or inhibit MMP. Pathogen-encoded mitochondrion-targeted proteins may or may not show amino acid sequence homology to Bcl-2-like proteins. Among the Bcl-2-unrelated, mitochondrion-targeted proteins, seve...

  18. Isolation and identification of proteins binding to the major breakpoint region(mbr) of bcl2 gene

    Institute of Scientific and Technical Information of China (English)

    Nan Yang; Yujie Sun; Changyan Ma

    2009-01-01

    Objective: We have previously found that mbr is a regulatory element of the bcl2 gene. The objective of this study is to isolate and identify the proteins binding to the 37 mbr in the 3 '-end of the mbr. Methods: Streptavidin magnetic particles were ligated to concatameric oligonucleofides of 37 mbr and incubated with the nuclear extracts of Jurkat cells. The DNA-binding proteins were eluted and then resolved by SDS-PAGE. After silver staining, the protein bands were excised and subjected to MALDI-TOF MS. Results: Several protein bands were detected after the isolation with magnetic particles, and Splicing factor, proline-and glutamine-rich(SFPQ), Poly(ADP-ribose)polymerase I(PARP), and promyelocytic leukemia protein(PML) were identified by MALDI-TOF MS. Conclusion: Several proteins were isolated and identified from the 37 mbr-protein complex. Results of this study establish a foundation for further study of the mechanisms by which mbr executes its regulatory function.

  19. Suppression of bcl-2 Gene by RNA Interference Increases Chemosensitivity to Cisplatin in Nasopharyngeal Carcinoma Cell Line CNE1

    Institute of Scientific and Technical Information of China (English)

    Zhi-Hua YIN; Cai-Ping REN; Feng LI; Xu-Yu YANG; Hui LI; Ming ZHAO; Kai-Tai YAO

    2004-01-01

    To explore the effect of suppressing BCL-2 expression using RNA interference (RNAi) technique in nasopharyngeal carcinoma cell line CNE1. CNE1 cell lines stably expressing shRNAs targeted bcl-2 and GL3 gene were established and gene expression inhibition was assessed by Western blotting analysis. The effect of suppressing bcl-2 by RNAi on cell growth was studied, the apoptosis induction and the sensitization of CNE 1 cells to cisplatin were quantified by MTT assay and flow cytometry. The results showed that: stable transfection of CNE 1 cells with vectors expressing shRNAs against bcl-2 decreased the expression of BCL-2 protein; suppression of BCL-2 expression did not affect cell proliferation but could increase the chemosensitivity to cisplatin in CNE1 cells. This will help physicians to make some clinical trials of gene therapy on nasopharyngeal carcinoma by RNAi.

  20. Identification of an HLA-A*0201 restricted Bcl2-derived epitope expressed on tumors

    DEFF Research Database (Denmark)

    Wang, Mingjun; Johansen, Britta; Nissen, Mogens H; Thorn, Mette; Kløverpris, Henrik; Fomsgaard, Anders; Buus, Søren; Claësson, Mogens H

    2006-01-01

    A large number of human tumor-associated antigen-derived peptides have been identified that are recognized by CTLs in a MHC-I restricted fashion. The apoptosis inhibitory protein Bcl2 is overexpressed in many human cancers as part of their neoplastic phenotype. Since inhibition or loss of Bcl2...... expression might impair tumor growth and survival, this protein may serve as a rational target for vaccine-induced CTL responses. By Western blot technique, we screened a panel of established human tumor cell lines for proteins involved in the apoptotic process. Two of eight tumor cell lines, a B lymphoma...... (Loukes) and a colon carcinoma (CCL220) cell line showed increased Bcl2 protein expression whereas the majority of tumor cell lines expressed proapoptotic proteins. Neither fibroblasts nor peripheral blood mononuclear cells showed Bcl2 expression. An HLA-A*0201 restricted CTL epitope was deduced in silica...

  1. Effect of Acupuncture plus Astragalus Polysaccharide on the Expression of Bcl-2 Protein in Islet  Cells in db/db Mice%针刺联合黄芪多糖对db/db小鼠胰岛β细胞Bcl-2蛋白表达的影响

    Institute of Scientific and Technical Information of China (English)

    张文奎; 李茜; 宫翠红; 孙志

    2016-01-01

    Objective To investigate the effect of acupuncture plus astragalus polysaccharide on the expression of Bcl-2 protein in pancreatic islet b cells in db/db mice. Method C57BL/Ksj-db/db mice as an animal model of spontaneous type 2 diabetes were selected for this experiment. Five-week-old db/db mice were randomized into model, acupuncture, medication and acupuncture+medication groups. Meanwhile, db/m mice were selected as a normal group. The acupuncture group received acupuncture at points Housanli (equivalent to Zusanli, ST36), Neiting(ST44) and Yishu(Extra) and the medication group, an oral gavage of astragalus polysaccharide (1400 mg/kg). Both groups were treated once daily, for 12 consecutive weeks. After the end of experiment, blood glucose, insulin and resistin were measured, and the expression of Bcl-2 protein in islet b cells was determined by immunohistochemical method. Result Blood glucose, insulin and resistin levels were significantly lower in the acupuncture+medication, acupuncture and medication groups than in the model group. They were significantly lower in the acupuncture+medication group than in the acupuncture and medication groups and significantly lower in the acupuncture group than in the medication group. The expression of Bcl-2 protein in islet b cells was higher in the medication, acupuncture and acupuncture+medication groups than in the model group; there was a statistically significant difference (P0.05). Conclusion Acupuncture plus astragalus polysaccharide can significantly reduce blood glucose and serum insulin and resistin levels and increase the expression of Bcl-2 protein in islet b cells to effectively inhibit apoptosis in islet b cells in db/db mice. Its effect is better than that of acupuncture alone or medication.%目的:观察针刺联合黄芪多糖对 db/db 小鼠胰岛b细胞 Bcl-2蛋白表达的影响。方法选用自发性2型糖尿病动物模型C57BL/Ksj-db/db 小鼠为本实验动物模型。将5周龄db/db 小鼠随

  2. Effects of systemic administration of ciliary neurotrophic factor on Bax and Bcl-2 proteins in the lumbar spinal cord of neonatal rats after sciatic nerve transection

    Directory of Open Access Journals (Sweden)

    A.C.S. Rezende

    2008-11-01

    Full Text Available Ciliary neurotrophic factor (CNTF is a cytokine that plays a neuroprotective role in relation to axotomized motoneurons. We determined the effect of daily subcutaneous doses of CNTF (1.2 µg/g for 5 days; N = 13 or PBS (N = 13 on the levels of mRNA for Bcl-2 and Bax, as well as the expression and inter-association of Bcl-2 and Bax proteins, and the survival of motoneurons in the spinal cord lumbar enlargement of 2-day-old Wistar rats after sciatic nerve transection. Five days after transection, the effects were evaluated on histological and molecular levels using Nissl staining, immunoprecipitation, Western blot analysis, and reverse transcriptase-polymerase chain reaction. The motoneuron survival ratio, defined as the ratio between the number of motoneurons counted on the lesioned side vs those on the unlesioned side, was calculated. This ratio was 0.77 ± 0.02 for CNTF-treated rats vs 0.53 ± 0.02 for the PBS-treated controls (P < 0.001. Treatment with CNTF modified the level of mRNA, with the expression of Bax RNA decreasing 18% (with a consequent decrease in the level of Bax protein, while the expression of Bcl-2 RNA was increased 87%, although the level of Bcl-2 protein was unchanged. The amount of Bcl-2/Bax heterodimer increased 91% over that found in the PBS-treated controls. These data show, for the first time, that the neuroprotective effect of CNTF on neonatal rat axotomized motoneurons is associated with a reduction in free Bax, due to the inhibition of Bax expression, as well as increased Bcl-2/Bax heterodimerization. Thus, the neuroprotective action of the CNTF on axotomized motoneurons can be related to the inhibition of this apoptotic pathway.

  3. SF Treg cells transcribing high levels of Bcl-2 and microRNA-21 demonstrate limited apoptosis in RA

    NARCIS (Netherlands)

    van der Geest, Kornelis S. M.; Smigielska, Katarzyna; Park, Ji-Ah; Abdulahad, Wayel H.; Kim, Hye-Won; Kroesen, Bart-Jan; van den Berg, Anke; Boots, Annemieke M. H.; Lee, Eun-Bong; Brouwer, Elisabeth

    2015-01-01

    Objective. The aim of this study was to investigate the turnover of Treg cells in the SF of RA patients. Methods. Treg cells were enumerated in peripheral blood and SF of RA patients and analysed by flow cytometry for expression of the proliferation marker Ki-67 and binding of the apoptosis marker a

  4. Apoptosis, p53, bcl-2, and Ki-67 in invasive bladder carcinoma: possible predictors for response to radiochemotherapy and successful bladder preservation

    International Nuclear Information System (INIS)

    Purpose: Several groups have reported the value of bladder preservation by a combined treatment protocol, including transurethral resection (TUR-B) and radiochemotherapy (RCT). As more experience is acquired with organ-sparing treatment, patient selection should be optimized. The purpose of this study was to investigate the role of several biologic markers that may predict response to RCT in muscle-invasive bladder carcinoma. Methods and Materials: The apoptotic index (AI), Ki-67, p53, and bcl-2 were evaluated by immunohistochemistry on pretreatment biopsies from 70 patients treated for invasive bladder cancer by TUR-B and RCT. Expression of each marker was correlated with initial response, local control, and cancer-specific survival with preserved bladder. An exploratory multivariate analysis was also performed that included clinical and immunohistochemical variables. Results: A high AI (> median = 1.6%) and a high Ki-67 index (> median = 8.8%), but not the p53- and bcl-2 expression, were significantly related to initial complete response (CR) and local control with preserved bladder after 5 years. When the AI and Ki-67 expression were considered simultaneously, the association with initial CR (p < 0.001), local control (p = 0.0002), and cancer-specific survival with preserved bladder (p = 0.008) was highly significant. In an exploratory multivariate analysis (final model), only AI, Ki-67, and the combined AI/Ki-67 variable retained significance for local control with preserved bladder at 5 years. Conclusion: Patients with a high spontaneous AI and a high pretreatment Ki-67 index should be considered preferentially for treatment with RCT, whereas tumors with low proliferation and low levels of apoptosis are less likely to respond to RCT

  5. 17β-Estradiol Inhibits Apoptosis in MCF-7 Cells, Inducing bcl-2 Expression via Two Estrogen-Responsive Elements Present in the Coding Sequence

    OpenAIRE

    Perillo, Bruno; Sasso, Annarita; Abbondanza, Ciro; Palumbo, Giuseppe

    2000-01-01

    We have found that 17β-estradiol induces bcl-2 transcription in human breast cancer MCF-7 cells. To identify cis-acting elements involved in this regulation, we have analyzed hormone responsiveness of transiently transfected reporter constructs containing the bcl-2 major promoter (P1). Hormone inducibility was observed only when either of two sequences, located within the bcl-2 coding region and showing one and two mutations with respect to the consensus estrogen-responsive element, were inse...

  6. Ekspresi Bcl-2 dan Caspase-3 Pascapaparan Hipoksia Hipobarik Intermiten

    Directory of Open Access Journals (Sweden)

    Achmad Hidayat

    2011-12-01

    Full Text Available Intermittent hypobaric hypoxia often suffered by cabin crew due to the fact that they are breathing lower pressured air inside the plane cabin. Human body will adapt by binding more oxygen and reducing hypoxia effect. Mitochondria function will be irritated by hypoxia which affect, outer mithochondrial membrane permeability due to decrease of Bcl-2 protein. Later on if hypoxia continues mitochondrial membrane will leaked cytocrome-c will released and apoptotic pathway will occur. The purpose of this study was to analyze Bcl-2 protein as antiapoptosis and caspase-3 as apoptosis indicator of intermittent hypobaric hypoxia exposure. Experimental study >was subjected to Spraque Dawley male mice during January–April 2010 by exposing them to several intermittent hypobaric hypoxias (one to four treatment in an interval of one week. Protein expression on mice heart cell were detected by immunohistochemistry in the Department of Pathology Anatomy Padjadjaran University-RS Dr. Hasan Sadikin Bandung and western blot methods in Department Biomolecullar Indonesia University Jakarta. Bcl-2 protein expressions increased according with the frequency of intermittent hypobaric hypoxia exposures while a reverse trend was found for caspase-3 protein expressions (rs=-0.448, p=0.013. From the study it can be concluded that apoptosis will be decreased as a result of intermittent hypobaric hypoxia exposures, which occurred from natural adaptation mechanism indicated by decrease of cell apoptosis and cardio protective effect will be emerged.

  7. The AML1/ETO fusion protein activates transcription of BCL-2

    OpenAIRE

    Klampfer, Lidija; Zhang, Jin; Zelenetz, Andrew O.; Uchida, Hideo; Nimer, Stephen D.

    1996-01-01

    The AML1 gene, located on chromosome 21, is involved in several distinct chromosomal translocations in human leukemia. In t(8;21) acute myelogenous leukemia (AML), the AML1 gene is juxtaposed to the ETO gene located on chromosome 8, generating an AML1/ETO fusion protein. Both AML1/ETO and the AML1 proteins recognize the same consensus DNA-binding motif (TGT/CGGT), which is found in the promoters of several genes involved in hematopoiesis. We found that two myeloid ...

  8. Ginkgo biloba extract mitigates liver fibrosis and apoptosis by regulating p38 MAPK, NF-κB/IκBα, and Bcl-2/Bax signaling

    Directory of Open Access Journals (Sweden)

    Wang YY

    2015-12-01

    Full Text Available Yuanyuan Wang, Rong Wang, Yujie Wang, Ruqin Peng, Yan Wu, Yongfang Yuan Department of Pharmacy, Shanghai 9th People’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People’s Republic of China Background: Liver fibrosis is the consequence of diverse liver injuries and can eventually develop into liver cirrhosis. Ginkgo biloba extract (GBE is an extract from dried ginkgo leaves that has many pharmacological effects because of its various ingredients and has been shown to be hepatoprotective. Purpose and methods: Aimed to investigate the underlying protective mechanisms of GBE on carbon tetrachloride (CCl4-induced liver fibrosis in rats. Male Sprague Dawley rats were randomly divided into four groups: control group (C, model group (M, low-dose group (L, and high-dose group (H. Liver fibrosis was induced by CCl4 groups M, L, and H: group C was administered saline. In addition, GBE at different doses was used to treat groups L and H. Results: The results of hematoxylin and eosin staining, Masson’s trichrome staining, a liver function index, and a liver fibrosis index showed that GBE application noticeably mitigated fibrosis and improved the function of the liver. The western blotting and immunohistochemistry analyses indicated that GBE reduced liver fibrosis not only by inhibiting p38 MAPK and NF-κBp65 via inhibition of IκBα degradation but also by inhibiting hepatocyte apoptosis via downregulation of Bax, upregulation of Bcl-2, and subsequent inhibition of caspase-3 activation. Inflammation-associated factors and hepatic stellate cell (HSC-activation markers further demonstrated that GBE could effectively inhibit HSC activation and inflammation as a result of its regulation of p38 MAPK and nuclear factor-kappa B/IκBα signaling. Conclusion: Our findings indicated a novel role for GBE in the treatment of liver fibrosis. The potential mechanisms may be associated with the following signaling pathways: 1 the p38 MAPK

  9. Triphala Extract Suppresses Proliferation and Induces Apoptosis in Human Colon Cancer Stem Cells via Suppressing c-Myc/Cyclin D1 and Elevation of Bax/Bcl-2 Ratio

    Directory of Open Access Journals (Sweden)

    Ramakrishna Vadde

    2015-01-01

    Full Text Available Colon cancer is the second leading cause of cancer related deaths in the USA. Cancer stem cells (CSCs have the ability to drive continued expansion of the population of malignant cells. Therefore, strategies that target CSCs could be effective against colon cancer and in reducing the risk of relapse and metastasis. In this study, we evaluated the antiproliferative and proapoptotic effects of triphala, a widely used formulation in Indian traditional medicine, on HCT116 colon cancer cells and human colon cancer stem cells (HCCSCs. The total phenolic content, antioxidant activity, and phytochemical composition (LC-MS-MS of methanol extract of triphala (MET were also measured. We observed that MET contains a variety of phenolics including naringin, quercetin, homoorientin, and isorhamnetin. MET suppressed proliferation independent of p53 status in HCT116 and in HCCSCs. MET also induced p53-independent apoptosis in HCCSCs as indicated by elevated levels of cleaved PARP. Western blotting data suggested that MET suppressed protein levels of c-Myc and cyclin D1, key proteins involved in proliferation, and induced apoptosis through elevation of Bax/Bcl-2 ratio. Furthermore, MET inhibited HCCSCs colony formation, a measure of CSCs self-renewal ability. Anticancer effects of triphala observed in our study warrant future studies to determine its efficacy in vivo.

  10. Apoptosis-related protein expression in rabbits with blast brain injury following early hyperbaric oxygen therapy

    Institute of Scientific and Technical Information of China (English)

    Shaonian Xu; Jiachuan Liu; Yongming Zhang; Chunlin Wang; Jinbiao Wang; Yanyan Yang; Jian Huo; Wenjiang Sun

    2012-01-01

    We treated detonator-explosion-induced craniocerebral injury in rabbits with hyperbaric oxygen 1-24 hours post-injury. Expression of the apoptosis-regulating protein cytochrome c, the pro-apoptotic protein Bax and the apoptosis marker caspase-3 in the tissues surrounding the area of injury was significantly reduced, while that of the anti-apoptotic protein Bcl-2 was significantly increased. Our findings indicate that the curative effects of early hyperbaric oxygen on cortical cell apoptosis is associated with suppression of cytochrome c release from mitochondria. This mechanism underlies the observed reduction in Bax expression and upregulation of Bcl-2 expression.

  11. Expression of Bcl-2 in cells with different telomerase activities

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Both telomerase and Bcl-2 are important genes in controlling apoptosis. The activation of telomerase and the abnormal regulation of Bcl-2 are also closely related to carcinogenesis. However, little is known about the linkage between telomerase and Bcl-2. The effect of activated telomerase on the expression of Bcl-2 has been investigated. It is demonstrated that in tumor and transformed cells with higher telomerase activity, Bcl-2 expression is significantly lower than that in telomerase negative or less telomerose activity cells. Further study showed that in the telomerase gene-transformed 2BS-fibroblasts, Bcl-2 expression is inhibited significantly while the exogenous telomerase catalytic subunit gene is re-expressed in fibroblasts. Results indicated that there might be a certain linkage between the expression of telomerase and Bcl-2, and overexpression of exogenous telomerase gene might down regulate the expression of Bcl-2.

  12. NF-κB, Bcl-2 and the alcoholic liver disease%NF-κB、Bcl-2与酒精性肝病

    Institute of Scientific and Technical Information of China (English)

    张曦; 王沁

    2011-01-01

    酒精性肝病(ALD)是由于长期过度饮酒而引发的一系列肝脏损害疾病.现研究表明肝细胞的凋亡对该病的发生、发展起着十分重要的作用.其中核因子κB (NF-κB)、B细胞淋巴瘤-2基因(Bcl-2)与ALD关系密切.ALD患者肝细胞内活化的NF-κB,通过刺激大量炎性细胞因子释放,引发肝组织炎症、纤维化、坏死和凋亡,同时通过调控凋亡蛋白酶 (Caspase)、Bcl-2、死亡受体等基因来干预肝细胞凋亡;被激活的Bcl-2,除本身具有抗凋亡功能外,还与NF-κB以复合物的形式发挥抗凋亡作用,同时与同家族促凋亡蛋白Bax以二聚体的形式依比例对肝细胞凋亡发挥抑制或促进作用.肝细胞凋亡和抗凋亡的动态失衡将成为酒精性肝病发病的重要途径之一.%Alcoholic liver disease which causes the liver damage is due to the long series of heavy drinking. Present study shows that the hepatocytes apoptosis plays an important role in the development of ALD. The nuclear factor ΚB (NF-ΚB) and B cell lymphoma-2 genes (Bcl-2) are closely related with the hepatocyte apoptosis. The activate NF-ΚB in the hepatocyte of ALD, not only can stimulate the release of inflammatory cytokines and cause liver inflammation, fibrosis, necrosis and apoptosis, but also can interfere the hepatocyte apoptosis by regulation the caspase (Caspase), Bcl-2, death receptor and other genes. The activated Bcl-2 not only can inhibit apoptosis by itself function, but also can inhibit apoptosis in the form of complex with the activated NF-ΚB. Bcl-2 can be dimer with the same family protein Bax which is the pro-apoptotic protein. The dimer inhibiting or stimulating apoptosis depends on the proportion of Bcl-2 and Bax. Imbalance of stimulating apoptosis and anti-apoptosis will become an important way in the way of ALD pathogenesy.

  13. Dentatin Induces Apoptosis in Prostate Cancer Cells via Bcl-2, Bcl-xL, Survivin Downregulation, Caspase-9, -3/7 Activation, and NF-κB Inhibition

    Directory of Open Access Journals (Sweden)

    Ismail Adam Arbab

    2012-01-01

    Full Text Available This study was set to investigate antiproliferative potential of dentatin (a natural coumarin isolated from Clausena excavata Burm. F against prostate cancer and to delineate the underlying mechanism of action. Treatment with dentatin dose-dependently inhibited cell growth of PC-3 and LNCaP prostate cancer cell lines, whereas it showed less cytotoxic effects on normal prostate epithelial cell line (RWPE-1. The inhibitory effect of dentatin on prostate cancer cell growth was due to induction of apoptosis as evidenced by Annexin V staining and cell shrinkage. We found that dentatin-mediated accumulation of reactive oxygen species (ROS and downregulated expression levels of antiapoptotic molecules (Bcl-2, Bcl-xL, and Survivin, leading to disruption of mitochondrial membrane potential (MMP, cell membrane permeability, and release of cytochrome c from the mitochondria into the cytosol. These effects were associated with induction of caspase-9, -3/7 activities, and subsequent DNA fragmentation. In addition, we found that dentatin inhibited TNF-α-induced nuclear translocation of p65, suggesting dentatin as a potential NF-κB inhibitor. Thus, we suggest that dentatin may have therapeutic value in prostate cancer treatment worthy of further development.

  14. 视网膜母细胞瘤Bcl-2和Bax基因蛋白质表达%Expression of Bcl-2 and Bax gene protein in retinoblastoma

    Institute of Scientific and Technical Information of China (English)

    张小猛; 庞利民; 张晓光

    2000-01-01

    目的:研究凋亡及凋亡调控基因Bcl-2/Bax和视网膜母细胞瘤(Retinoblastoma,RB)的发生、发展及退化的关系.方法:收集36例RB标本,对其分别进行Bcl-2和Bax基因的蛋白质免疫组织化学染色.对其表达情况和染色强度进行观察.结果:①Bcl-2在分化型RB中表达比较好;②Bax在未分化型和分化型中表达都比较好.结论:①分化型和未分化型RB中都有Bcl-2/Bax基因蛋白表达;②随RB恶性度的增加,Bcl-2的表达逐渐减弱;Bax的表达无明显改变.③分化型RB受Bcl-2和Bax基因共同控制;未分化型RB受Bax基因调控,Bcl-2基因发挥很少的作用.

  15. Cyanide-induced Death of Dopaminergic Cells is Mediated by Uncoupling Protein-2 Up-regulation and Reduced Bcl-2 Expression

    OpenAIRE

    Zhang, X.; Li, L.; Zhang, L.; Borowitz, J.L.; Isom, G.E.

    2009-01-01

    Cyanide is a potent inhibitor of mitochondrial oxidative metabolism and produces mitochondria-mediated death of dopaminergic neurons and sublethal intoxications are associated with a Parkinson-like syndrome. Cyanide toxicity is enhanced when mitochondrial uncoupling is stimulated following up-regulation of uncoupling protein-2 (UCP-2). In this study, the role of a pro-survival protein, Bcl-2, in cyanide-mediated cell death was determined in a rat dopaminergic immortalized mesencephalic cell l...

  16. Silver Nanoparticles Biosynthesized Using Achillea biebersteinii Flower Extract: Apoptosis Induction in MCF-7 Cells via Caspase Activation and Regulation of Bax and Bcl-2 Gene Expression

    Directory of Open Access Journals (Sweden)

    Javad Baharara

    2015-02-01

    Full Text Available Silver nanoparticles (Ag-NPs, the most popular nanoparticles, possess unique properties. Achillea biebersteinii is a plant of the Asteraceae family rich in active antitumor components. The aim of this research was the characterization and investigation of the cytotoxic properties of Ag-NPs synthesized using A. biebersteinii flower extract, on a human breast cancer cell line. The Ag-NPs were synthesized after approximately 180 min of reaction at 40 °C, then they were characterized by UV-visible spectroscopy, Fourier transform infrared spectroscopy (FTIR, transmission electron microscopy (TEM and dynamic light scattering (DLS. The anti-apoptosis effect of Ag-NPs on the MCF-7 cell line was investigated by MTT assay, DAPI and acridine orange staining and caspase activity. The transcriptional expression of bax, bcl-2, caspase-3, -8 and -9 were also evaluated by RT-PCR. The TEM images revealed that the Ag-NPs morphology had a different shape. The DLS indicated that the average hydrodynamic diameter of the biosynthesized Ag-NPs was around 12 nm. By UV-visible spectroscopy the strongest absorbance peak was observed at 460 nm. The FTIR results also showed interaction between the plant extract and Ag-NPs due to the similarity in the peak patterns. The EDS results showed that Ag-NPs display an absorption peak at 3 keV, indicating the presence of the element silver. The Ag-NPs caused a dose-dependent decrease in cell viability, fragmentation in nucleic acid, inhibited the proliferation and induction of apoptosis on MCF-7 by suppressing specific cell cycle genes, and simulation programmed cell dead genes. Further investigation is required to establish the potential of this novel and promising approach in cancer therapy.

  17. Persea declinata (Bl. Kosterm Bark Crude Extract Induces Apoptosis in MCF-7 Cells via G0/G1 Cell Cycle Arrest, Bcl-2/Bax/Bcl-xl Signaling Pathways, and ROS Generation

    Directory of Open Access Journals (Sweden)

    Putri Narrima

    2014-01-01

    Full Text Available Persea declinata (Bl. Kosterm is a member of the Lauraceae family, widely distributed in Southeast Asia. It is from the same genus with avocado (Persea americana Mill, which is widely consumed as food and for medicinal purposes. In the present study, we examined the anticancer properties of Persea declinata (Bl. Kosterm bark methanolic crude extract (PDM. PDM exhibited a potent antiproliferative effect in MCF-7 human breast cancer cells, with an IC50 value of 16.68 µg/mL after 48 h of treatment. We observed that PDM caused cell cycle arrest and subsequent apoptosis in MCF-7 cells, as exhibited by increased population at G0/G1 phase, higher lactate dehydrogenase (LDH release, and DNA fragmentation. Mechanistic studies showed that PDM caused significant elevation in ROS production, leading to perturbation of mitochondrial membrane potential, cell permeability, and activation of caspases-3/7. On the other hand, real-time PCR and Western blot analysis showed that PDM treatment increased the expression of the proapoptotic molecule, Bax, but decreased the expression of prosurvival proteins, Bcl-2 and Bcl-xL, in a dose-dependent manner. These findings imply that PDM could inhibit proliferation in MCF-7 cells via cell cycle arrest and apoptosis induction, indicating its potential as a therapeutic agent worthy of further development.

  18. Persea declinata (Bl.) Kosterm Bark Crude Extract Induces Apoptosis in MCF-7 Cells via G0/G1 Cell Cycle Arrest, Bcl-2/Bax/Bcl-xl Signaling Pathways, and ROS Generation.

    Science.gov (United States)

    Narrima, Putri; Paydar, Mohammadjavad; Looi, Chung Yeng; Wong, Yi Li; Taha, Hairin; Wong, Won Fen; Ali Mohd, Mustafa; Hadi, A Hamid A

    2014-01-01

    Persea declinata (Bl.) Kosterm is a member of the Lauraceae family, widely distributed in Southeast Asia. It is from the same genus with avocado (Persea americana Mill), which is widely consumed as food and for medicinal purposes. In the present study, we examined the anticancer properties of Persea declinata (Bl.) Kosterm bark methanolic crude extract (PDM). PDM exhibited a potent antiproliferative effect in MCF-7 human breast cancer cells, with an IC50 value of 16.68 µg/mL after 48 h of treatment. We observed that PDM caused cell cycle arrest and subsequent apoptosis in MCF-7 cells, as exhibited by increased population at G0/G1 phase, higher lactate dehydrogenase (LDH) release, and DNA fragmentation. Mechanistic studies showed that PDM caused significant elevation in ROS production, leading to perturbation of mitochondrial membrane potential, cell permeability, and activation of caspases-3/7. On the other hand, real-time PCR and Western blot analysis showed that PDM treatment increased the expression of the proapoptotic molecule, Bax, but decreased the expression of prosurvival proteins, Bcl-2 and Bcl-xL, in a dose-dependent manner. These findings imply that PDM could inhibit proliferation in MCF-7 cells via cell cycle arrest and apoptosis induction, indicating its potential as a therapeutic agent worthy of further development. PMID:24808916

  19. Effect of 147Pm β-irradiation on bcl-2 gene and bax gene expression in human leukemia cells

    International Nuclear Information System (INIS)

    Objective: To study the effect of exposure to a pure β radiator-147Pm on bcl-2 gene expression in human leukemia HL-60 cells. Methods: Immunohistochemical technique was used to identify the expression of bcl-2 and bax proteins in HL-60 cells, as well as RNA dot blot hybridization to show the expression of bcl-2 mRNA in HL-60 cells. Results: The expression of bcl-2 protein was as high as 88% in control human HL-60 cells. Down regulation of bcl-2 protein expression which lowered to 53% was noted after exposure to 147Pm. The expression of bax protein was low in control cells, and after irradiation it did not obviously change. An obvious down regulation of bcl-2 mRNA expression was found in irradiated HL-60 cells. With increasing time of 147Pm exposure, the down regulation of bcl-2 became more evident. Conclusion: The apoptotic action of 147Pm β-rays in human HL-60 cells is associated with the down regulation of the apoptosis-suppressing gene bcl-2

  20. Mito-priming as a method to engineer Bcl-2 addiction

    Science.gov (United States)

    Lopez, Jonathan; Bessou, Margaux; Riley, Joel S.; Giampazolias, Evangelos; Todt, Franziska; Rochegüe, Tony; Oberst, Andrew; Green, Douglas R.; Edlich, Frank; Ichim, Gabriel; Tait, Stephen W. G.

    2016-01-01

    Most apoptotic stimuli require mitochondrial outer membrane permeabilization (MOMP) in order to execute cell death. As such, MOMP is subject to tight control by Bcl-2 family proteins. We have developed a powerful new technique to investigate Bcl-2-mediated regulation of MOMP. This method, called mito-priming, uses co-expression of pro- and anti-apoptotic Bcl-2 proteins to engineer Bcl-2 addiction. On addition of Bcl-2 targeting BH3 mimetics, mito-primed cells undergo apoptosis in a rapid and synchronous manner. Using this method we have comprehensively surveyed the efficacy of BH3 mimetic compounds, identifying potent and specific MCL-1 inhibitors. Furthermore, by combining different pro- and anti-apoptotic Bcl-2 pairings together with CRISPR/Cas9-based genome editing, we find that tBID and PUMA can preferentially kill in a BAK-dependent manner. In summary, mito-priming represents a facile and robust means to trigger mitochondrial apoptosis. PMID:26833356

  1. Studies on Cytotoxicity of Glaucocalyxin A, C and Its Relation with Bcl-2 Protein%蓝萼甲、丙素细胞毒活性及其与Bcl-2蛋白关系的研究

    Institute of Scientific and Technical Information of China (English)

    嵇源源; 高立文; 张健; 王剑文

    2013-01-01

    目的:研究蓝萼甲素(GLA)和蓝萼丙素(GLC)对15株不同类型的肿瘤细胞的细胞毒性差异以及与Bcl-2蛋白的关系.方法:采用MTT法检测细胞存活率;用Western Blotting检测细胞凋亡关键蛋白Bcl-2的表达;应用分子对接Autodock程序,将GLA和GLC与Bcl-2蛋白进行分子对接,比较其结合的差异性.结果:用MTT法结果表明GLA对所选用的15株肿瘤细胞均有显著的抑制作用,而相同浓度的GLC对15株肿瘤细胞的生存率没有影响;用分子对接法结果显示GLA与Bcl-2蛋白的结合自由能和ki值均低于GLC.结论:GLA更易与Bcl-2蛋白结合从而抑制Bcl-2蛋白的功能,促进细胞凋亡.

  2. Aiolos transcription factor controls cell death in T cells by regulating Bcl-2 expression and its cellular localization.

    Science.gov (United States)

    Romero, F; Martínez-A, C; Camonis, J; Rebollo, A

    1999-01-01

    We searched for proteins that interact with Ras in interleukin (IL)-2-stimulated or IL-2-deprived cells, and found that the transcription factor Aiolos interacts with Ras. The Ras-Aiolos interaction was confirmed in vitro and in vivo by co-immunoprecipitation. Indirect immunofluorescence shows that IL-2 controls the cellular distribution of Aiolos and induces its tyrosine phosphorylation, required for dissociation from Ras. We also identified functional Aiolos-binding sites in the Bcl-2 promoter, which are able to activate the luciferase reporter gene. Mutation of Aiolos-binding sites within the Bcl-2 promoter inhibits transactivation of the reporter gene luciferase, suggesting direct control of Bcl-2 expression by Aiolos. Co-transfection experiments confirm that Aiolos induces Bcl-2 expression and prevents apoptosis in IL-2-deprived cells. We propose a model for the regulation of Bcl-2 expression via Aiolos. PMID:10369681

  3. Effect of Bcl-2 rs956572 polymorphism on age-related gray matter volume changes.

    Science.gov (United States)

    Liu, Mu-En; Huang, Chu-Chung; Yang, Albert C; Tu, Pei-Chi; Yeh, Heng-Liang; Hong, Chen-Jee; Chen, Jin-Fan; Liou, Ying-Jay; Lin, Ching-Po; Tsai, Shih-Jen

    2013-01-01

    The anti-apoptotic protein B-cell CLL/lymphoma 2 (Bcl-2) gene is a major regulator of neural plasticity and cellular resilience. Recently, the Bcl-2 rs956572 single nucleotide polymorphism was proposed to be a functional allelic variant that modulates cellular vulnerability to apoptosis. Our cross-sectional study investigated the genetic effect of this Bcl-2 polymorphism on age-related decreases in gray matter (GM) volume across the adult lifespan. Our sample comprised 330 healthy volunteers (191 male, 139 female) with a mean age of 56.2±22.0 years (range: 21-92). Magnetic resonance imaging and genotyping of the Bcl-2 rs956572 were performed for each participant. The differences in regional GM volumes between G homozygotes and A-allele carriers were tested using optimized voxel-based morphometry. The association between the Bcl-2 rs956572 polymorphism and age was a predictor of regional GM volumes in the right cerebellum, bilateral lingual gyrus, right middle temporal gyrus, and right parahippocampal gyrus. We found that the volume of these five regions decreased with increasing age (all P<.001). Moreover, the downward slope was steeper among the Bcl-2 rs956572 A-allele carriers than in the G-homozygous participants. Our data provide convergent evidence for the genetic effect of the Bcl-2 functional allelic variant in brain aging. The rs956572 G-allele, which is associated with significantly higher Bcl-2 protein expression and diminished cellular sensitivity to stress-induced apoptosis, conferred a protective effect against age-related changes in brain GM volume, particularly in the cerebellum. PMID:23437205

  4. Effect of Bcl-2 rs956572 polymorphism on age-related gray matter volume changes.

    Directory of Open Access Journals (Sweden)

    Mu-En Liu

    Full Text Available The anti-apoptotic protein B-cell CLL/lymphoma 2 (Bcl-2 gene is a major regulator of neural plasticity and cellular resilience. Recently, the Bcl-2 rs956572 single nucleotide polymorphism was proposed to be a functional allelic variant that modulates cellular vulnerability to apoptosis. Our cross-sectional study investigated the genetic effect of this Bcl-2 polymorphism on age-related decreases in gray matter (GM volume across the adult lifespan. Our sample comprised 330 healthy volunteers (191 male, 139 female with a mean age of 56.2±22.0 years (range: 21-92. Magnetic resonance imaging and genotyping of the Bcl-2 rs956572 were performed for each participant. The differences in regional GM volumes between G homozygotes and A-allele carriers were tested using optimized voxel-based morphometry. The association between the Bcl-2 rs956572 polymorphism and age was a predictor of regional GM volumes in the right cerebellum, bilateral lingual gyrus, right middle temporal gyrus, and right parahippocampal gyrus. We found that the volume of these five regions decreased with increasing age (all P<.001. Moreover, the downward slope was steeper among the Bcl-2 rs956572 A-allele carriers than in the G-homozygous participants. Our data provide convergent evidence for the genetic effect of the Bcl-2 functional allelic variant in brain aging. The rs956572 G-allele, which is associated with significantly higher Bcl-2 protein expression and diminished cellular sensitivity to stress-induced apoptosis, conferred a protective effect against age-related changes in brain GM volume, particularly in the cerebellum.

  5. EGFR and Bcl-2 in gastric mucosa of children infected with Helicobacter pylori

    Directory of Open Access Journals (Sweden)

    Ewa Ryszczuk

    2016-03-01

    Full Text Available Aim: The aim of the study was to evaluate the expression of EGFR and Bcl-2 proteins as inhibitory markers of apoptosis in surface epithelial cells and gland cells of antral gastric mucosa in children infected with Helicobacter pylori according to the severity and activity of antral gastritis and to assess the correlation between the number of cells expressing EGFR and the number of cells expressing Bcl-2 in H. pylori infected children. Materials and methods: The study included 44 children: 68.2% with chronic gastritis and positive IgG against H. pylori, and 31.8% with functional disorders of the gastrointestinal tract and with normal IgG against H. pylori. The evaluation of EGFR expression in gastric mucosa was performed immunohistochemically using monoclonal mouse anti-EGFR antibody. The polyclonal antibody was used to determine the expression of anti-Bcl-2. Results: A significant increase in the number of cells expressing EGFR and Bcl-2 protein was found in the epithelial cells in severe as well as mild and moderate gastritis in the group of children infected with H. pylori. An increase in the number of cells expressing EGFR and Bcl-2 protein was also found in the epithelial cells in group I according to the activity of gastritis. There was a statistically significant positive correlation between the numbers of cells expressing EGFR and Bcl-2 in H. pylori infected children. Conclusion: Increased expression of EGFR and Bcl-2 proteins in the epithelial cells and a statistically significant positive correlation between the numbers of cells expressing EGFR and Bcl-2 in H. pylori infected children could suggest increased regeneration abilities of gastric mucosa.

  6. bcl-2 expression is not associated with survival in metastatic cutaneous melanoma: A historical cohort study

    Directory of Open Access Journals (Sweden)

    Corleta Oly C

    2008-06-01

    Full Text Available Abstract Background Programmed cell death (apoptosis has been implicated in tumor development and may affect the metastatic potential of tumor cells. The role of bcl-2, a proto-oncogene that inhibits apoptosis, has been studied in several malignancies, including cutaneous melanoma (CM. The purpose of this study was to evaluate the immunohistochemical expression of bcl-2 in 35 regional lymph node, 28 subcutaneous and 17 visceral CM metastases, correlating the findings with patient survival. Methods In a historical cohort study patient survival was correlated with the expression of bcl-2 in regional lymph node, subcutaneous and visceral metastases of CM. Eighty slides containing surgical specimens from 50 patients diagnosed with stage III and IV CM, 28 male (56% and 22 female (44%, were analyzed. Mean age at diagnosis was 43 years (16–74 years; median = 42 years. Mean Breslow depth was 5.01 mm (0.4–27.5 mm. The slides were submitted to immunohistochemical reaction using anti-bcl-2 monoclonal antibody and classified according to the degree of staining ( 50% of tumor cells stained. The relationship between bcl-2 protein expression and survival for each type of metastasis, gender and age at initial diagnosis was analyzed. Results Mean overall survival was 33.9 months after the diagnosis of the initial metastatic lesion (range: 0 to 131 months. Twenty-four out of 50 patients (48% had died from CM by the end of the study period. bcl-2 expression was detected in 74.3, 85.7 and 82.4% of lymph node, subcutaneous and visceral metastases, respectively. After univariate and multivariate analyses, no correlation was found between positive bcl-2 expression and overall survival for the types of metastases evaluated. Conclusion The immunohistochemical expression of bcl-2 in metastasis alone is not a prognostic marker for CM.

  7. DNA Hypermethylation of CREB3L1 and Bcl-2 Associated with the Mitochondrial-Mediated Apoptosis via PI3K/Akt Pathway in Human BEAS-2B Cells Exposure to Silica Nanoparticles

    Science.gov (United States)

    Zou, Yang; Li, Qiuling; Jiang, Lizhen; Guo, Caixia; Li, Yanbo; Yu, Yang; Li, Yang; Duan, Junchao; Sun, Zhiwei

    2016-01-01

    The toxic effects of silica nanoparticles (SiNPs) are raising concerns due to its widely applications in biomedicine. However, current information about the epigenetic toxicity of SiNPs is insufficient. In this study, the epigenetic regulation of low-dose exposure to SiNPs was evaluated in human bronchial epithelial BEAS-2B cells over 30 passages. Cell viability was decreased in a dose- and passage-dependent manner. The apoptotic rate, the expression of caspase-9 and caspase-3, were significantly increased induced by SiNPs. HumanMethylation450 BeadChip analysis identified that the PI3K/Akt as the primary apoptosis-related pathway among the 25 significant altered processes. The differentially methylated sites of PI3K/Akt pathway involved 32 differential genes promoters, in which the CREB3L1 and Bcl-2 were significant hypermethylated. The methyltransferase inhibitor, 5-aza, further verified that the DNA hypermethylation status of CREB3L1 and Bcl-2 were associated with downregulation of their mRNA levels. In addition, mitochondrial-mediated apoptosis was triggered by SiNPs via the downregulation of PI3K/Akt/CREB/Bcl-2 signaling pathway. Our findings suggest that long-term low-dose exposure to SiNPs could lead to epigenetic alterations. PMID:27362941

  8. Altered expression of cellular Bcl-2 in the progression of hamster cholangiocarcinogenesis.

    Science.gov (United States)

    Jeon, Byung-Suk; Yoon, Byung-Il

    2012-01-01

    Bcl-2 is an intracytoplasmic and membrane-associated apoptosis suppressor, and its overexpression is closely associated with survival of malignant tumors, in particular their aggressive behavior and poor prognosis. The role of Bcl-2 is, however, still controversial in cholangiocarcinogenesis because of the discrepancies in the expression of the protein. In the present study, alteration in the expression of Bcl-2 in cholangiocarcinogenesis was investigated by studying the immunoreactivities of this protein in normal, hyperplastic bile ducts with or without dysplastic changes, and neoplastic bile duct cells from a hamster cholangiocarcinoma (ChC) model. Cytoplasmic staining, which reflects high-Bcl-2 immunoreactivity, was negative to very weak in normal and hyperplastic bile ducts without dysplastic changes, while hyperplastic bile ducts with dysplasia indicated heterogeneously strong expression. On the other hand, most of the neoplastic cells of invasive cholangiocarcinomas were negative to weak as much as the level of normal bile ducts. The results suggest that the antiapoptotic factor Bcl-2 plays a limited role in the survival of highly proliferative, potentially dysplastic bile duct cells. However, the role of Bcl-2 in biliary cancer cells was not significant. PMID:22654601

  9. RBP2 Promotes Adult Acute Lymphoblastic Leukemia by Upregulating BCL2.

    Directory of Open Access Journals (Sweden)

    Xiaoming Wang

    Full Text Available Despite recent increases in the cure rate of acute lymphoblastic leukemia (ALL, adult ALL remains a high-risk disease that exhibits a high relapse rate. In this study, we found that the histone demethylase retinoblastoma binding protein-2 (RBP2 was overexpressed in both on-going and relapse cases of adult ALL, which revealed that RBP2 overexpression was not only involved in the pathogenesis of ALL but that its overexpression might also be related to relapse of the disease. RBP2 knockdown induced apoptosis and attenuated leukemic cell viability. Our results demonstrated that BCL2 is a novel target of RBP2 and supported the notion of RBP2 being a regulator of BCL2 expression via directly binding to its promoter. As the role of RBP2 in regulating apoptosis was confirmed, RBP2 overexpression and activation of BCL2 might play important roles in ALL development and progression.

  10. Apoptose e expressão de Bcl-2 e das caspases 3 e 8 em placenta bovina, em diferentes estádios de gestação Apoptosis and expression of Bcl-2 and caspases 3 and 8 in placenta of cows at different pregnancy stages

    Directory of Open Access Journals (Sweden)

    K.K.O.L. Meça

    2010-04-01

    Full Text Available Apoptose e seus mecanismos reguladores são eventos fisiológicos cruciais para a manutenção da homeostase placentária, e o desequilíbrio desses processos pode comprometer a função placentária e, consequentemente, o sucesso da gravidez. Neste estudo, investigou-se a apoptose utilizando-se histomorfometria em lâminas coradas em HE e submetidas à reação de TUNEL. Além disso, avaliou-se a expressão de Bcl-2 e das caspases 8 e 3, pela reação de polimerase em cadeia em tempo real, em placentas saudáveis em diferentes estádios de gestação. Amostras de placentônios de vacas com quatro, seis e nove meses de gestação foram colhidas e processadas. O índice apoptótico aumentou progressivamente com o avanço da gestação. Tanto o Bcl-2 quanto as caspases 3 e 8 foram expressas nos três períodos estudados, sendo a expressão de Bcl-2 menor que a de caspase 8, que é menor que a de caspase 3. Estes resultados indicam que essas moléculas estão envolvidas na via apoptótica ativada na maturação placentária, exibindo um padrão de expressão ao longo da gestação e contribuindo para o equilíbrio fisiológico da celularidade e renovação celular na placenta bovina.Apoptosis and its regulating mechanisms are crucial physiological events for the maintenance of the placental homostasis; and disequilibrium of these processes may compromise placental function and the success of the pregnancy. In this study, apoptosis was investigated by histomorphometry using slides stained with HE and TUNEL reaction. Besides that, Bcl-2 and caspases 8 and 3 expression were evaluated by real time polymerase chain reaction in healthy placentas under different gestacional ages. Samples of placentones of cows at 4th, 6th, and 9th months of gestation were harvested and processed. The apoptotic index gradually increased with the advance of the gestation. Bcl-2 and caspases 3 and 8 were expressed in all the studied periods, being the expression of Bcl-2

  11. Serum level of IL13 and expression of BCL2 in Behcet's disease

    Directory of Open Access Journals (Sweden)

    Hanan.M.A Darwish*, Sabila Gomaa Mousa** Noha Hamdy

    2006-09-01

    Full Text Available Background BD: BCL2 family is a large family of apoptosis regulating proteins consisting of both blockers and promoters of cell death. Immunological processes and a variety of cytokines may play a role in pathophysiological process. Defective regulation of programmed cell death (apoptosis also play a role in development of Behcet's disease Objective: To investigate the level of BCL2 and IL13in BD and to determine their to relation monitory disease activity. Patients and methods: This study was conducted on thirty patients (15 active and 15 inactive and 15-health control, the activity of BD was evaluated according to international study group for BD disease, using ELISA technique for IL 13 and flow cytometry forBCL2. Results: Elevated serum levels of IL13 in patient with active BD than inactive and both had elevated levels than control(P< 0.01 and also the serum levels of Bcl2 was elevated in patient with active BD than inactive and control(P< 0.01. Concolusion: The data suggested that IL13 and BCL2 could be involved in the pathogenesis of BD and its serum levels can be used as marker to monitor disease activity.

  12. Effect of Achyranthes bidentata polysaccharides on the expression of BCL-2 and bax in hepatic tissues after exhaustive exercise in rats.

    Science.gov (United States)

    Lin, Jinyang; Zhang, Zhuoying; Shan, Ying

    2010-01-01

    This study aims to assess the effects of Achyranthes bidentata polysaccharides (ABPS) on the expression of bcl-2 and bax in hepatic tissues after exhaustive exercise in order to provide theoretical support for the application of ABPS in the field of sports nutrition. Thirty male Sprague-Dawley rats were randomized into three groups, each consisting of 10 rats: Normal control group (NCG), Exhausting exercises control group (EECG), ABPS treated group (ATG). ABPS were fed orally by gastric intubation to rats of ABPS treated group (ATG) once daily for 7 days. Control animals (EECG and NCG) received the same amount of isotonic sodium chloride solution. Exhaustive exercise was performed on a rodent treadmill. The SP (streptavidin peroxidase) method for immunohistochemical staining was adopted to test the protein expression of bax and bcl-2 in the hepatic tissues of the rats. Exhausting exercises increased bax protein expression of hepatic tissues of rats and bax/bcl-2 ratio dramatically, but a decreased bcl-2 protein expression. In the rats fed ABPS orally by gastric intubation, the bax protein expression and bax/bcl-2 ratio obviously decreased, while bcl-2 protein expression increased. The result indicated that bax and bcl-2 co-regulated the exercise-induced hepatocyte apoptosis. Feeding ABPS orally by gastric intubation to rats can inhibit the hepatocyte apoptosis in exhaustive exercise. PMID:21731162

  13. Effect of captopril and paraquat on expression of p53 and Bcl-2 genes and proteins in rat lung tissue using RT-PCR and immunohistochemistry

    Directory of Open Access Journals (Sweden)

    Azizi E

    2008-10-01

    Full Text Available "n Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Arial; mso-bidi-theme-font:minor-bidi;} Background: Paraquat is an herbicide produced and used prevalently worldwide. Studies have shown that lung fibrosis induced by paraquat can be prevented or delayed by certain antioxidants, iron chelating agents, melatonin, and, recently, blood pressure lowering drugs such as captopril."n"n Methods: The protective effects of captopril on paraquat toxicity were studied using RT-PCR and immunohistochemistry to determine the gene and protein expression of p53 and Bcl-2 in lung tissue samples from rats treated with captopril before and after exposure to paraquat."n"n Results: We found no significant difference in the gene and protein expression of p53 in different tissue samples, except for mRNA levels in the lung tissue of captopril-treated rats. However, the protein expression of Bcl-2 is greater in tissue from rats exposed to paraquat alone and paraquat together with pre- and posttreatment with captopril compared to tissue from untreated control rats and from those treated with captopril alone, which can be due to inflammatory responses of lung tissue. By RT-PCR, we were unable to detect Bcl-2 in lung tissue samples."n"n Conclusion: These results show that paraquat does not induce significant DNA damage; therefore, the

  14. Clinical significance of co-expression of MYC and BCL2 protein in aggressive B-cell lymphomas treated with a second line immunochemotherapy.

    Science.gov (United States)

    Miura, Katsuhiro; Takahashi, Hiromichi; Nakagawa, Masaru; Izu, Asami; Sugitani, Masahiko; Kurita, Daisuke; Sakagami, Masashi; Ohtake, Shimon; Uchino, Yoshihito; Hojo, Atsuko; Kodaira, Hitomi; Yagi, Mai; Kobayashi, Yujin; Iriyama, Noriyoshi; Kobayashi, Sumiko; Kiso, Satomi; Hirabayashi, Yukio; Hatta, Yoshihiro; Takei, Masami

    2016-06-01

    The clinical significance of concurrent expression of MYC and BCL2 protein, known as "double-expressor lymphoma" (DEL), among patients with relapsed or refractory aggressive B-cell lymphomas, remains unclear. A retrospective analysis was performed of 38 patients treated with a salvage treatment consisting of rituximab, ifosfamide, etoposide, cytarabine and dexamethasone followed by consolidative high-dose chemotherapies. A total of 17 cases (45%) were categorized as DEL using immunohistochemical assay with a cut-off value of positivity of 40% for MYC and 50% for BCL2, respectively. DEL was associated with a lower overall response rate (35% vs 71%, p = 0.0481), worse 2-year progression-free survival (9% vs 67%, p = 0.001) and overall survival (35% vs 71%, p = 0.037). This analysis suggests that DEL is common among patients with relapsed/refractory aggressive B-cell lymphomas and that such patients require novel treatment strategies. PMID:26390147

  15. The Study of Pentoxifylline Drug Effects on Renal Apoptosis and BCL-2 Gene Expression Changes Following Ischemic Reperfusion Injury in Rat

    OpenAIRE

    Hashemi, Mehrdad

    2014-01-01

    Ischemia Reperfusion injury is the tissue damage caused when blood supply returns to the tissue after a period of ischemia or lack of oxygen. In this study, the effect of pentoxyfylline on BCL-2 gene expression changes and cell injury in kidney of rat following Ischemia Reperfusion were evaluated. In this experimental study, 20 male wistar rats with average weight of 250-300 g were selected and then were accidently divided them on two tenth group of control and treatment groups. In the contro...

  16. Two independent positive feedbacks and bistability in the Bcl-2 apoptotic switch.

    Directory of Open Access Journals (Sweden)

    Jun Cui

    Full Text Available BACKGROUND: The complex interplay between B-cell lymphoma 2 (Bcl-2 family proteins constitutes a crucial checkpoint in apoptosis. Its detailed molecular mechanism remains controversial. Our former modeling studies have selected the 'Direct Activation Model' as a better explanation for experimental observations. In this paper, we continue to extend this model by adding interactions according to updating experimental findings. METHODOLOGY/PRINCIPAL FINDINGS: Through mathematical simulation we found bistability, a kind of switch, can arise from a positive (double negative feedback in the Bcl-2 interaction network established by anti-apoptotic group of Bcl-2 family proteins. Moreover, Bax/Bak auto-activation as an independent positive feedback can enforce the bistability, and make it more robust to parameter variations. By ensemble stochastic modeling, we also elucidated how intrinsic noise can change ultrasensitive switches into gradual responses. Our modeling result agrees well with recent experimental data where bimodal Bax activation distributions in cell population were found. CONCLUSIONS/SIGNIFICANCE: Along with the growing experimental evidences, our studies successfully elucidate the switch mechanism embedded in the Bcl-2 interaction network and provide insights into pharmacological manipulation of Bcl-2 apoptotic switch as further cancer therapies.

  17. Up-regulation of Bcl-2 is required for the progression of prostate cancer cells from an androgen-dependent to an androgen-independent growth stage

    Institute of Scientific and Technical Information of China (English)

    Yuting Lin; Junichi Fukuchi; Richard A Hiipakka; John M Kokontis; Jialing Xiang

    2007-01-01

    Bcl-2 is an anti-apoptotic oncoprotein and its protein levels are inversely correlated with prognosis in many cancers.However, the role of Bcl-2 in the progression of prostate cancer is not clear. Here we report that Bcl-2 is required for the progression of LNCaP prostate cancer cells from an androgen-dependent to an androgen-independent growth stage. The mRNA and protein levels of Bcl-2 are significantly increased in androgen-independent prostate cancer cells, shRNA-mediated gene silencing of Bcl-2 in androgen-independent prostate cancer cells promotes UV-induced apoptosis and suppresses the growth of prostate tumors in vivo. Growing androgen-dependent cells under androgen-deprivation conditions results in formation of androgen-independent colonies; and the transition from androgen-dependent to androgen-independent growth is blocked by ectopic expression of the Bcl-2 antagonist Bax or Bcl-2 shRNA. Thus, our results demonstrate that Bcl-2 is not only critical for the survival of androgen-independent prostate cancer cells, but is also required for the progression of prostate cancer cells from an androgen-dependent to an androgen-independent growth stage.

  18. Expansion of human and murine hematopoietic stem and progenitor cells ex vivo without genetic modification using MYC and Bcl-2 fusion proteins.

    Directory of Open Access Journals (Sweden)

    Gregory A Bird

    Full Text Available The long-term repopulating hematopoietic stem cell (HSC population can self-renew in vivo, support hematopoiesis for the lifetime of the individual, and is of critical importance in the context of bone marrow stem cell transplantation. The mechanisms that regulate the expansion of HSCs in vivo and in vitro remain unclear to date. Since the current set of surface markers only allow for the identification of a population of cells that is highly enriched for HSC activity, we will refer to the population of cells we expand as Hematopoietic Stem and Progenitor cells (HSPCs. We describe here a novel approach to expand a cytokine-dependent Hematopoietic Stem and Progenitor Cell (HSPC population ex vivo by culturing primary adult human or murine HSPCs with fusion proteins including the protein transduction domain of the HIV-1 transactivation protein (Tat and either MYC or Bcl-2. HSPCs obtained from either mouse bone marrow, human cord blood, human G-CSF mobilized peripheral blood, or human bone marrow were expanded an average of 87 fold, 16.6 fold, 13.6 fold, or 10 fold, respectively. The expanded cell populations were able to give rise to different types of colonies in methylcellulose assays in vitro, as well as mature hematopoietic populations in vivo upon transplantation into irradiated mice. Importantly, for both the human and murine case, the ex vivo expanded cells also gave rise to a self-renewing cell population in vivo, following initial transplantation, that was able to support hematopoiesis upon serial transplantation. Our results show that a self-renewing cell population, capable of reconstituting the hematopoietic compartment, expanded ex vivo in the presence of Tat-MYC and Tat-Bcl-2 suggesting that this may be an attractive approach to expand human HSPCs ex vivo for clinical use.

  19. Evidence that inhibition of BAX activation by BCL-2 involves its tight and preferential interaction with the BH3 domain of BAX

    Institute of Scientific and Technical Information of China (English)

    Bonsu Ku; Chengyu Liang; Jae U Jung; Byung-Ha Oh

    2011-01-01

    Interactions between the BCL-2 family proteins determine the cell's fate to live or die. How they interact with each other to regulate apoptosis remains as an unsettled central issue. So far, the antiapoptotic Bc1-2 proteins are thought to interact with BAX weakly, but the physiological significance of this interaction has been vague.Herein, we show that recombinant BCL-2 and BCL-w interact potently with a BCL-2 homology (BH) 3 domain-containing peptide derived from BAX, exhibiting the dissociation constants of 15 and 23 nM, respectively. To clarify the basis for this strong interaction, we determined the three-dimensional structure of a complex of BCL-2 with a BAX peptide spanning its BH3 domain. It revealed that their interactions extended beyond the canonical BH3 domain and involved three nonconserved charged residues of BAX. A novel BAX variant, containing the alanine substitution of these three residues, had greatly impaired affinity for BCL-2 and BCL-w, hut was otherwise indistinguishable from wild-type BAX. Critically, the apoptotic activity of the BAX variant could not be restrained by BCL-2 and BCL-w, pointing that the observed tight interactions are critical for regulating BAX activation. We also comprehensively quantified the binding affinities between the three BCL-2 subfamily proteins. Collectively, the data show that due to the high affinity of BAX for BCL-2, BCL-w and A1, and of BAK for BCL-XL, MCL-1 and A1, only a subset of BH3-only proteins, commonly including BIM, BID and PUMA, could he expected to free BAX or BAK from the antiapoptotic BCL-2 proteins to elicit apoptosis.

  20. 特发性脊柱侧凸椎旁肌组织Bcl-2蛋白表达及细胞凋亡的研究%Apoptosis and expression of Bcl-2 in the paraspinal muscles of idiopathic scoliosis

    Institute of Scientific and Technical Information of China (English)

    赵宇; 邱贵兴

    2004-01-01

    BACKGROUND: The etiology of idiopathic scoliosis is still uncertain. The paraspinal muscles have been implicated by several investigators as a possible causative factor in the production and progression of adolescent idiopathic scoliosis. Therefore, the role of the spinal musculature in the pathogenesis of scoliosis has been the subject of much investigation.OBJECTIVE: This study focused on the expressive difference among Bcl-2,Caspase-3 and bcl-x of the thoracic spinal musculature on convex side with those on the concave side in the scoliosis patients in order to explore the possible mechanism which paraspinal muscles play on scoliosis from the view of molecular biology.DESIGN:A randomized case-control study was conducted.SETTING and PARTICIPANTS: This research was completed in Department of Orthopaedics of Peking Union Hospital. Two patients with bursting fracture of thoracic vertebra and lumbar were selected as control group. The research group was composed by 10 patients which including 2 males and 8 females with scoliosis of thoracic vertebra, aged from 12 to 17 years old,mean age was 14. 3. The average Cobb angel was 57.7°(ranged from 45°~85°).INTERVENTION: Paraspinal muscles were taken from both sides during surgery from the apex of the curve between the 6th and 11th thoracic vertebral levels. Part of the tissue was fixed in formalin and stained with hematoxylin and eosin; the remaining tissue was snap frozen and processed for immunohistochemistry and Western blotting.muscles.RESULTS: The expression of Bcl-2 in convex side of paraspinal muscles was reduced. There was no difference between scoliosis patients and control group on cell apoptosis because it could be seen in both groups. Compared with concave side of scoliosis and control group, the muscle fibers were much thinner in convex side.CONCLUSION: The asymmetry of paraspinal muscles caused by anomaly of nerve and muscles may be the important factor which leads to the development of idiopathic

  1. 儿童成熟B-NHL中BCL-2、BCL-6蛋白表达及其临床病理意义%BCL-2 and BCL-6 protein expression in pediatric B-cell Non-Hodgkin′s lymphoma and its clinic-pathologic significance

    Institute of Scientific and Technical Information of China (English)

    王舒静; 俞懿; 高怡瑾; 孟建华; 陆凤娟; 李军; 王宏胜; 翟晓文; 苗慧; 钱晓文

    2014-01-01

    Objective The study was designed to investigate the protein expression of BCL-2 and BCL-6 in children with B-NHL and its clinic-pathological significance.Method Between July 1999 and October 2011,92 untreated patients (age 16 years or less)with newly diagnosed B-NHL (including BL, DLBCL and BL/DLBCL)were enrolled.We use the immunohistochemical technique (Envision TM)to detect BCL-2,BCL-6 protein expression levels.The expression of BCL-2 and BCL-6 and its association with clinic-pathological features and prognosis were analyzed.Results BCL-2 protein expression was performed in 47 B-NHL,the rate of positivity in BL and DLBCL were 9 .7% (3/3 1 ) and 33 .3%(5/15),respectively.There was significant difference between them (P=0.047).However,there was no association between the expression of BCL-2 and gender,stage and prognosis (P>0.05 ).BCL-6 protein expression was performed in 31 B-NHL,The 2-year EFS was 83.3% for children with BCL-6 protein expression,the other was 45.5%,there was significant difference between them (P=0.019). Children with positive BCL-6 protein expression had better prognosis.Conclusion BCL-2 protein expression was useful for distinguish BL from DLBCL and BCL-6 protein expression is a prognosis factor of B-NHL.%目的初步探讨儿童成熟B细胞非霍奇金淋巴瘤(B-NHL)中BCL-2、BCL-6蛋白表达及其临床病理意义。方法收集1999-2011年复旦大学附属儿科医院血液科收治的92例初治儿童B-NHL资料,包括伯基特淋巴瘤(burkitl lymphoma,BL)53例,弥漫大B细胞性淋巴瘤(DLBCL)38例,以及介于BL与DLBCL之间未能分类的B细胞淋巴瘤(BL/DLBCL)1例。92例患儿年龄≤16岁。所有病例均经过2家三级甲等医院病理科诊断。通过免疫组织化学技术检测儿童B-NHL中BCL-2、BCL-6蛋白表达情况。结果(1)92例儿童B-NHL中47例进行BCL-2蛋白检测,BCL-2表达阳性率在BL和DLBCL中分别为9.7%(3/31)和33.3%(5/15),差

  2. α-2b干扰素对瘢痕疙瘩成纤维细胞凋亡及端粒酶逆转录酶、bcl-2 mRNA表达的影响%Effects of IFNα-2b on cell apoptosis and expression of hTERT and bcl-2 mRNA in keloid fibroblasts

    Institute of Scientific and Technical Information of China (English)

    黄勇; 孟强; 邢新

    2008-01-01

    目的 观察α-2b干扰素(IFNα-2b)对瘢痕疙瘩成纤维细胞生长增殖、凋亡及端粒酶逆转录酶(hTERT)、bcl-2 mRNA表达的影响,探讨其在瘢痕疙瘩治疗中的作用机制.方法 进行成纤维细胞原代培养,细胞分别来自8例瘢痕疙瘩标本和8例正常皮肤标本.第3~4代的细胞用于实验.以IFNa-2b作用于体外培养的瘢痕疙瘩和正常皮肤成纤维细胞,MTT法检测成纤维细胞生长增殖情况,应用流式细胞仪观察处理后成纤维细胞凋亡,RT-PCR法检测成纤维细胞hTERT和bcl-2mRNA的表达.结果 IFNα-2b对瘢痕疙瘩和正常皮肤成纤维细胞生长有抑制作用,体外培养的瘢痕疙瘩和正常皮肤成纤维细胞经10 000 U/ml IFNα-2b处理后,能诱导成纤维细胞凋亡发生,RT-PCR检测hTERT和bcb2 mRNA表达降低,和对照组相比,差异有统计学意义(P<0.01),且具有明显的时间依赖性.结论 作为一个负性调节因子,IFNα-2b能抑制瘢痕疙瘩成纤维细胞的生长增殖并诱导成纤维细胞发生调亡,下调成纤维细胞端粒酶活性是其重要作用机制之一.通过抑制端粒酶活性进行抗瘢痕疙瘩治疗可能是一个新途径.%Objective To observe the effects of IFNα-2b on keloid fibroblasts in cell prolifera-tion, apoptosis, expression of hTERT and bcl-2 mRNA and to explore its anti-keloid mechanism. Methods Primary cultures of dermal fibroblasts derived from 8 keloid and 8 normal skin samples were established, strains of fibroblasts at passages 3 to 4 were used in this study. Keloid and normal skin fibroblasts in culture medium in vitro were given IFNα-2b and were obsevered in different time. The proliferation of the fibroblasts was measured by MTT assay, the apoptosis was analysed by flow cytometry(FCM), and the expression of hTERT and bcl-2 mRNA were obsevered by semi-qnantitativere verse transcriptase-polymerase chain reaction (RT-PCR). The data were analyzed by statistical software (SPSS11. 5). Results IFNα-2

  3. Influence of oxidative stress on apoptosis and expression of bax and bcl-2 of enterocytes in burn rats with delayed resuscitation on the plateau%高原地区烧伤后延迟复苏氧化应激对大鼠肠上皮细胞凋亡及bax和bcl-2基因表达的影响

    Institute of Scientific and Technical Information of China (English)

    周文军; 张诚; 刘毅; 刘萍; 马明; 张世范

    2009-01-01

    Objective To explore influence of oxidative stress reaction on apoptosis rate and expres-sion of apoptosis-related genes bax and bcl-2 of enterocytes in severely burned rats with delayed resuscitation on the plateau. Methods One hundred and twenty rats subjected to 30% TBSA full-thickness scald on the back were derided into plateau experimental group (PE, altitude 3840 m) and Lanzhou experimental group (LE, altitude 1517 m). Then LE and PE groups were subdivided into Lanzhou immediate fluid resus-citation group (LIFR, with immediate intraperitoneal injection of isotonic saline after scald, 40 mL/kg), Lanzhou delayed fluid resuscitation group [LDFR, with intraperitoneal injection of isotonic saline at 6 post scald hour (PSH), 40 mL/kg], and plateau immediate fluid resuscitation group (PIFR, with immediate in-traperitoneal injection of isotonic saline after scald, 40 mL/kg), plateau delayed fluid resuscitation group (PDFR, with intraperitoneal injection of isotonic saline at 6 PSH, 40 mL/kg). Another 12 rats were divided into Lanzhou sham scald group (LS) and plateau sham scald group (PS), with 6 rats in each group. Rats in LS and PS groups were sham scalded in a water bath for 15 s without fluid infusion. Rats were sacrificed at 6, 12, 24, 48, 72 PSH for collection of small intestine samples to determine the contents of malonaldehyde (MDA) and total hydrosulfide (TSH). The apoptosis of enterocytes was determined by TUNEL, and the ex-pression of bax and bcl-2 in epithelial cells were observed by immunohistochemical method. Intestinal sample of LS and PS groups were collected to determine the contents of MDA and TSH. Results After being scal-ded, content of MDA in intestinal tissue of rats in LDFR group and PDFR group was respectively greater than that in LIFR group and PIFR group (P<0.05 or P<0.01). Intestinal tissue content of MDA of rats in LDFR group (9.8±4.0 nmol/mg) and PDFR group (10.2±1.3 nmol/mg) was respectively greater than that in LIFR group (9.5±2

  4. Downregulation of uPAR and cathepsin B induces apoptosis via regulation of Bcl-2 and Bax and inhibition of the PI3K/Akt pathway in gliomas.

    Directory of Open Access Journals (Sweden)

    Ramarao Malla

    Full Text Available BACKGROUND: Glioma is the most commonly diagnosed primary brain tumor and is characterized by invasive and infiltrative behavior. uPAR and cathepsin B are known to be overexpressed in high-grade gliomas and are strongly correlated with invasive cancer phenotypes. METHODOLOGY/PRINCIPAL FINDINGS: In the present study, we observed that simultaneous downregulation of uPAR and cathepsin B induces upregulation of some pro-apoptotic genes and suppression of anti-apoptotic genes in human glioma cells. uPAR and cathepsin B (pCU-downregulated cells exhibited decreases in the Bcl-2/Bax ratio and initiated the collapse of mitochondrial membrane potential. We also observed that the broad caspase inhibitor, Z-Asp-2, 6-dichlorobenzoylmethylketone rescued pCU-induced apoptosis in U251 cells but not in 5310 cells. Immunoblot analysis of caspase-9 immunoprecipitates for Apaf-1 showed that uPAR and cathepsin B knockdown activated apoptosome complex formation in U251 cells. Downregulation of uPAR and cathepsin B also retarded nuclear translocation and interfered with DNA binding activity of CREB in both U251 and 5310 cells. Further western blotting analysis demonstrated that downregulation of uPAR and cathepsin B significantly decreased expression of the signaling molecules p-PDGFR-β, p-PI3K and p-Akt. An increase in the number of TUNEL-positive cells, increased Bax expression, and decreased Bcl-2 expression in nude mice brain tumor sections and brain tissue lysates confirm our in vitro results. CONCLUSIONS/SIGNIFICANCE: In conclusion, RNAi-mediated downregulation of uPAR and cathepsin B initiates caspase-dependent mitochondrial apoptosis in U251 cells and caspase-independent mitochondrial apoptosis in 5310 cells. Thus, targeting uPAR and cathepsin B-mediated signaling using siRNA may serve as a novel therapeutic strategy for the treatment of gliomas.

  5. Characterization of vNr-13, the first alphaherpesvirus gene of the bcl-2 family

    International Nuclear Information System (INIS)

    The Bcl-2 family, including antiapoptotic and proapoptotic members, plays key regulating roles in programmed cell death. We report the characterization of a new member of the bcl-2 family, encoded by herpesvirus of turkeys (HVT). The product of this gene shares 80% homology with Nr-13, an apoptosis inhibitor, which is overexpressed in avian cells transformed by the v-src oncogene. This new gene, that we propose to call vnr-13, is the first member of the bcl-2 family to be isolated among α-herpesviruses. Results from cells expressing the HVT-vnr-13 gene product show that the encoded protein inhibits apoptosis and also reduces the rate of cellular proliferation. Contrary to all bcl-2 homologues found in γ-herpesvirus, which are intronless, vnr-13 has the same organization as the cellular nr-13 gene. Hence, the HVT vnr-13 gene may have been acquired from a reverse transcriptase product of an unspliced precursor RNA, or via direct recombination with the host chromosomal DNA

  6. 8周中等强度低负荷量训练对老龄雌性大鼠骨骼肌Bax和Bcl-2蛋白及SIRT1/SIRT3信号轴基因表达的影响%Effects of 8-week medium intensity low load training on proteins Bax and Bcl-2 and the gene expression of signal axis SIRT1/SIRT3 of skeletal muscle of aged female rats

    Institute of Scientific and Technical Information of China (English)

    李方晖; 肖琳; 覃飞; 刘承宜

    2014-01-01

    In order to observe the effects of 8-week medium intensity low load training on the levels of proteins Bax and Bcl-2 and the gene messenger RNA (mRNA) expression of axis sirtuin 1 (SIRT1)/sirtuin 3 (SIRT3) of gastrocne-mius of aged rats, the authors divided 16 18-month old female SD rats randomly into a control group and an exercise group, each of which contained 8 rats, let the rats in the exercise group do an aerobic exercise on a treadmill for con-secutive 8 weeks, at a speed of 15 km/h (with 60%~75%VO2max), 15 minutes a day, 5 days a week, let the rats in the control group live freely, in 24 hours after rat exercising at the end of week 8, killed the rats, measured gastrocnemius index, measured the levels of proteins Bax and Bcl-2 of gastrocnemius by means of Western blot analysis, measured the mRNA levels of SIRT3, SIRT1, manganese superoxide dismutase (MnSOD), Caspase 3, peroxisome prolifera-tor-activated receptor-γcoactivator-1 (PGC-1α), mitochondrial transcription factor A (TFAM) and nuclear respiratory factor 1 (NRF1) by means of RT-PCR, and revealed the following findings:as for the rats in the exercise group, their gastrocnemius mass and gastrocnemius index increased significantly (P<0.05 and P<0.01 respectively), their protein Bax level decreased significantly (P<0.05), their protein Bcl-2 level and Bcl-2/Bax ratio increased significantly (P<0.05);their mRNA levels of SIRT3, SIRT1, PGC-1α, NRF1, TFAM and MnSOD increased significantly (P<0.05), their mRNA level of Caspase-3 decreased significantly (P<0.05). The said findings indicated the followings:medium intensity low load training could delay the changing of muscle cell apoptosis signal of aged rats; the homeostatic mechanism mediated by axis SIRT1/SIRT3 played an important role in medium intensity low load training increasing the mitochondria refreshing rate and antioxidase level of skeletal muscle of aged rats.%观察8周中等强度低负荷量训练对老龄雌性大鼠腓肠肌Bax和Bcl-2

  7. Phenylboronic acid-functionalized polyamidoamine-mediated Bcl-2 siRNA delivery for inhibiting the cell proliferation.

    Science.gov (United States)

    Wu, Di; Yang, Jiebing; Xing, Zhen; Han, Haobo; Wang, Tingting; Zhang, Aijun; Yang, Yan; Li, Quanshun

    2016-10-01

    In this study, the conjugation of phenylboronic acid (PBA) to amine-terminated polyamidoamine (PAMAM) was successfully conducted to prepare a tumor-targeted gene carrier PBA-functionalized PAMAM (PPP) for Bcl-2 siRNA delivery, using a heterobifunctional crosslinker NHS-PEG5k-Mal. The carrier possessed favorable capacity for siRNA condensation and could protect siRNA from the degradation against RNase and serum. The introduction of PBA could facilitate the cellular uptake and further transfection of Bcl-2 siRNA demonstrated by confocal laser scanning microscopy and flow cytometry. Meanwhile, PPP-mediated transfection of Bcl-2 siRNA could significantly inhibit the expression of Bcl-2 gene at both mRNA and protein levels. Furthermore, owing to the knock-down of Bcl-2, PPP/siRNA could significantly inhibit the cell proliferation by inducing the cell apoptosis, and also enhance the antitumor efficiency of doxorubicin by suppressing the resistance of tumor cells to chemotherapeutics. In conclusion, the PPP-mediated Bcl-2 siRNA delivery could potentially be an effective platform for solving the drug resistance and further achieving the combined chemotherapy and gene therapy in tumor treatment. PMID:27371891

  8. Bcl-2 and N-Myc Coexpression Increases IGF-IR and Features of Malignant Growth in Neuroblastoma Cell Lines

    Directory of Open Access Journals (Sweden)

    Rama Jasty

    2001-01-01

    Full Text Available The bcl-2 and c-myc oncogenes cooperate to transform multiple cell types. In the pediatric malignancy NB2, Bcl2 is highly expressed. In tumors with a poor prognosis, N-Myc, a protein homologous to c-Myc, is overexpressed as a result of gene amplification. The present study was designed to determine whether Bcl-2 cooperates with N-Myc to bestow a tumorigenic phenotype to neuroblastoma (NB cells. NB cell lines that at baseline express neither Bcl-2 nor N-Myc were stably transfected to express these gene products. In this model, we found Bcl-2 rescues N-Myc-expressing cells from apoptosis induced by serum withdrawal. Coexpression of Bcl-2 and N-Myc supports growth in low serum conditions and anchorage-independent growth in soft agar. Similarly, in vivo tumorigenic and angiogenic activity was dependent on coexpression. Our data further suggests that the mechanism underlying these changes involves the receptor for insulin growth factor type I (IGF-IR.

  9. Time Dependent Bladder Apoptosis Induced by Acute Bladder Outlet Obstruction and Subsequent Emptying is Associated with Decreased MnSOD Expression and Bcl-2/Bax Ratio

    OpenAIRE

    Li, Wen Ji; Shin, Mi-Kyung; Oh, Seung-June

    2010-01-01

    Ischemia/reperfusion (I/R) injury-induced oxidative stress plays an important role in the functional impairment of the bladder following acute bladder outlet obstruction (BOO) via induction of apoptosis. The purpose of this study was to investigate the time course of the bladder apoptosis, and apoptosis related molecular changes in the early stage of acute BOO. Twelve-week-old male Sprague Dawley rats were divided into control, acute BOO only (I), and acute BOO plus subsequent emptying (I/R) ...

  10. NDV-induced apoptosis in absence of Bax; evidence of involvement of apoptotic proteins upstream of mitochondria

    Directory of Open Access Journals (Sweden)

    Molouki Aidin

    2012-08-01

    Full Text Available Abstract Background Recently it was shown that following infection of HeLa cells with Newcastle disease virus (NDV, the matrix (M protein binds to Bax and subsequently the intrinsic pathway of apoptosis is activated. Moreover, there was very little alteration on mRNA and protein levels of Bax and Bcl-2 after infection with NDV. Finding In order to further investigate the role of members of the Bcl-2 family, Bax-knockout and wild-type HCT116 cells were infected with NDV strain AF2240. Although both cells underwent apoptosis through the activation of the intrinsic pathway and the release of cytochrome c from mitochondria, the percentage of dead Bax-knockout cells was significantly lower than wt cells (more than 10% at 48 h post-infection. In a parallel experiment, the effect of NDV on HT29 cells, that are originally Bcl-2-free, was studied. Apoptosis in HT29 cells was associated with Bax redistribution from cytoplasm to mitochondria, similar to that of HeLa and wt HCT116 cells. Conclusion Although the presence of Bax during NDV-induced apoptosis contributes to a faster cell death, it was concluded that other apoptotic protein(s upstream of mitochondria are also involved since cancer cells die whether in the presence or absence of Bax. Therefore, the classic Bax/Bcl-2 ratio may not be a major determinant in NDV-induced apoptosis.

  11. A Study on Evaluation of Apoptosis and Expression of Bcl-2-Related Marker in Wound Healing of Streptozotocin-Induced Diabetic Rats

    OpenAIRE

    Surya Bhan; Rahul Mitra; Arya, A. K.; Pandey, H. P.; Tripathi, K.

    2013-01-01

    Uncontrolled blood sugar is a major cause of vascular complications and delayed wound healing in diabetes mellitus. During wound healing process, normally, apoptosis is responsible for events such as removal of inflammatory cells and evolution of granulation tissue into scar which occur during the late phase of wound healing. Early apoptosis can lead to abnormal wound healing by removing granulation tissue including fibroblast, endothelial cell, and small vessels. To determine the role of apo...

  12. 5-HT2 receptor blocker sarpogrelate prevents downregulation of antiapoptotic protein Bcl-2 and protects the heart against ischemia-reperfusion injury.

    Science.gov (United States)

    Rajesh, Katare Gopalrao; Suzuki, Ryoko; Maeda, Hironori; Murio, Yamamoto; Sasaguri, Shiro

    2006-09-27

    Even though reperfusion is the treatment of choice in patients admitted with acute myocardial infarction, reperfusion itself has been demonstrated to activate various pathological factors especially following procedures of cardiac revascularization. 5-hydroxytryptamine (5HT) is one such factor activated during reperfusion and is known to trigger the post ischemic contractile dysfunction and pathological apoptosis. Here we demonstrate the potential effects of the 5-HT(2)A antagonist sarpogrelate in protecting the myocardium against reperfusion injury of heart. Male Wistar rats weighing between 220 and 240 g were subjected to 30 min left coronary artery (LCA) occlusion and 120 min reperfusion. Sarpogrelate (4 mg/kg) was infused intravenously for 30 min either before LCA occlusion or at reperfusion. Following reperfusion the samples were collected for infarction area, immunohistochemistry, western blotting and myocardial metabolite analysis. Sarpogrelate infusion before ischemia resulted in (a) significant recovery of post ischemic cardiac functions (LVDP, EDP), (b) significant reduction in the infarct size among the risk area after triphenyl tetrazolium chloride staining (p<0.001), (c) decreased tissue water content (p<0.05), (d) well preserved myocardial ATP (p<0.05), (e) reduction in Bcl-2 downregulation and caspase 3 activation and (g) less prevalence of apoptotic cells (3.1+/-0.4% to 15.2+/-0.6%, drug versus control). Treating the rats with sarpogrelate during reperfusion also showed similar results. This study thus demonstrates the protective effects of sarpogrelate and supports the role for 5-HT2A inhibition in preventing the reperfusion injury of the heart. PMID:16876202

  13. Effects of human interleukin 10 gene transfer on the expression of Bcl-2 Bax and apoptosis of hepatocyte in rats with acute hemorrhagic necrotizing pancreatitis

    Institute of Scientific and Technical Information of China (English)

    GU Jun-chao; WANG Yu; ZHANG Zhong-tao; XUE Jian-guo; LI Jian-she; ZHOU Yan-zhong

    2005-01-01

    @@ Acute necrotising pancreatitis is characterized by inflammatory and necrotic events, which follow the initial intra-acinar injury involving enzyme activation, and disruption of the acinar cytoskeleton.1 At present, apoptosis has become a hot topic in many kinds of disease.

  14. Conditional knockdown of BCL2A1 reveals rate-limiting roles in BCR-dependent B-cell survival.

    Science.gov (United States)

    Sochalska, M; Ottina, E; Tuzlak, S; Herzog, S; Herold, M; Villunger, A

    2016-04-01

    Bcl2 family proteins control mitochondrial apoptosis and its members exert critical cell type and differentiation stage-specific functions, acting as barriers against autoimmunity or transformation. Anti-apoptotic Bcl2a1/Bfl1/A1 is frequently deregulated in different types of blood cancers in humans but its physiological role is poorly understood as quadruplication of the Bcl2a1 gene locus in mice hampers conventional gene targeting strategies. Transgenic overexpression of A1, deletion of the A1-a paralogue or constitutive knockdown in the hematopoietic compartment of mice by RNAi suggested rate-limiting roles in lymphocyte development, granulopoiesis and mast cell activation. Here we report on the consequences of conditional knockdown of A1 protein expression using a reverse transactivator (rtTA)-driven approach that highlights a critical role for this Bcl2 family member in the maintenance of mature B-cell homeostasis. Furthermore, we define the A1/Bim (Bcl-2 interacting mediator of cell death) axis as a target of key kinases mediating B-cell receptor (BCR)-dependent survival signals, such as, spleen tyrosine kinase (Syk) and Brutons tyrosine kinase (Btk). As such, A1 represents a putative target for the treatment of B-cell-related pathologies depending on hyperactivation of BCR-emanating survival signals and loss of A1 expression accounts, in part, for the pro-apoptotic effects of Syk- or Btk inhibitors that rely on the 'BH3-only' protein Bim for cell killing. PMID:26450454

  15. Inclusion Complex of Zerumbone with Hydroxypropyl-β-Cyclodextrin Induces Apoptosis in Liver Hepatocellular HepG2 Cells via Caspase 8/BID Cleavage Switch and Modulating Bcl2/Bax Ratio

    Directory of Open Access Journals (Sweden)

    Nabilah Muhammad Nadzri

    2013-01-01

    Full Text Available Zerumbone (ZER isolated from Zingiber zerumbet was previously encapsulated with hydroxypropyl-β-cyclodextrin (HPβCD to enhance ZER’s solubility in water, thus making it highly tolerable in the human body. The anticancer effects of this new ZER-HPβCD inclusion complex via apoptosis cell death were assessed in this study for the first time in liver hepatocellular cells, HepG2. Apoptosis was ascertained by morphological study, nuclear stain, and sub-G1 cell population accumulation with G2/M arrest. Further investigations showed the release of cytochrome c and loss of mitochondrial membrane potential, proving mitochondrial dysfunction upon the ZER-HPβCD treatment as well as modulating proapoptotic and anti-apototic Bcl-2 family members. A significant increase in caspase 3/7, caspase 9, and caspase 8 was detected with the depletion of BID cleaved by caspase 8. Collectively, these results prove that a highly soluble inclusion complex of ZER-HPβCD could be a promising anticancer agent for the treatment of hepatocellular carcinoma in humans.

  16. Effect of Exercise Training on Bcl-2 and Bax Gene Expression in the Rat Heart

    Directory of Open Access Journals (Sweden)

    Jafari

    2015-10-01

    Full Text Available Background Apoptosis or programmed cell death plays an important role in the development of cardiovascular diseases, particularly heart failure. Current evidence suggests that exercise training may alter apoptosis-related signaling in sensitive somatic tissues such as the myocardium. Objectives The aim of this study was to assess the effect of exercise training on Bcl-2 and Bax genes expression as key molecules involved in intrinsic pathway of apoptosis in the rat heart. Materials and Methods This study was conducted with a two-group experimental design (animal model and sixteen three-month-old male rats were selected and randomly divided to two groups of exercise training (n = 8 and control (n = 8. Rats in the trained group participated in an exercise training program for 12 weeks (10 – 60 m min-1, 24 – 33 min d-1, 15%. The rat hearts were removed forty-eight hours after the last training session. RNA extraction and synthesis of cDNA was done, and Bax and Bcl2 genes expression was analyzed through the Real Time-Polymerase Chain Reaction (RT-PCR. Kolmogorov-Smirnov and independent t-test were applied for statistical analysis of the data (P 0.05. However, Bcl2 expression was higher in the trained group compared to the control group (11%. Conclusions In general, it seems that three-month exercise training was effective in reducing cardiac mitochondrial pro-apoptotic protein. However, considering the results of the Bcl2 gene expression, more researches are needed to identify effects of exercise trainings on indices of myocardial apoptosis.

  17. Analysis of the Expression of Fas, FasL and Bcl-2 in the Pathogenesis of Autoimmune Thyroid Disorders

    Institute of Scientific and Technical Information of China (English)

    Shenren Chen; S.M.Fazle Akbar; Zhichao Zhen; Yiping Luo; Lijuan Deng; Haihua Huang; Linxin Chen; Wei Li

    2004-01-01

    To investigate the expression of apoptosis-related protein (Fas, FasL, and Bcl-2) in the pathogenesis of autoimmune thyroid disorders (ATDs), immunohistochemical staining was performed on 20 Hashimoto's thyroiditis (HT), 20 Graves' disease (GD), and 20 thyroid follicular adenoma (TFA, as control). All the cases expressed Fas, mainly on the cell surface and cytoplasm. FasL was found in 17 cases of the TFA. Bcl-2 was detected in 15 cases of HT, 19 of GD and 17 of TFA. In TFA, a moderate Fas expression and a minimal or no FasL expression was detected on follicular cells. In HT, the follicles adjacent to infiltrating lymphocytes showed increased levels of Fas and FasL expression. A weaker staining of Fas and FasL was exhibited on infiltrating lymphocytes than on thyrocytes. In a comparison of GD with HT, thyrocytes and lymphocytes showed similar Fas staining, but for FasL the staining was rather weaker in HT. The expression of Bcl-2 was nearly identical in GD and TFA, but much weaker on the follicular cells in vicinity of lymphocytes and on the lymphocytes located in germinal centers of HT tissues. The expression of Fas, FasL, Bcl-2 in Hashimoto's thyroiditis and Graves' disease were almost same. FasL strong expression and Bcl-2 weak expression on the follicles in HT may induce apoptosis. These results provided evidence for expression of Fas, FasL and Bcl-2 in the pathogenesis of autoimmune thyroid disease. The lymphocytes seem not to be directly engaged in the process via their own FasL, but they may provide some cytokines that, in turn, upregulate Fas and/or FasL expression to induce apoptosis.

  18. Evaluation of Bcl-2 Family Gene Expression in Hippocampus of 3, 4-methylenedioxymethamphetamine Treated Rats

    Directory of Open Access Journals (Sweden)

    Hamed Hashemi-Nasl

    2012-01-01

    Full Text Available Objective: 3,4-methylenedioxymethamphetamine (MDMA is an illicit, recreational drugthat causes cellular death and neurotoxicity. This study evaluates the effects of differentdoses of MDMA on the expression of apoptosis–related proteins and genes in the hippocampusof adult rats.Materials and Methods: In this expremental study,a total of 20 male Sprague Dawley rats(200-250 g were treated with MDMA (0, 5, 10, 20 mg/kg i.p. twice daily for 7 days. Sevendays after the last administration of MDMA, the rats were killed. Bax and Bcl-2 genesin addition to protein expressions were detected by western blot and reverse transcriptionpolymerasechain reaction (RT-PCR.Results were analyzed using one-way ANOVA andp≤0.05 was considered statistically significant.Results: Our results showed that MDMA caused dose dependent up-regulation of Baxand down-regulation of Bcl-2 in the hippocampus. There was a significant alteration inbcl-2 and bax genes density.Conclusion: Changes in apoptosis-related proteins and respective genes relating to Baxand Bcl-2 might be involved in the molecular mechanism of MDMA-induced apoptosis.

  19. Cannabinoids Regulate Bcl-2 and Cyclin D2 Expression in Pancreatic β Cells

    Science.gov (United States)

    Kim, Jung Seok; Rho, Jun Gi; Shin, Jung Jae; Song, Woo Keun; Lee, Eun Kyung; Egan, Josephine M.; Kim, Wook

    2016-01-01

    Recent reports have shown that cannabinoid 1 receptors (CB1Rs) are expressed in pancreatic β cells, where they induce cell death and cell cycle arrest by directly inhibiting insulin receptor activation. Here, we report that CB1Rs regulate the expression of the anti-apoptotic protein Bcl-2 and cell cycle regulator cyclin D2 in pancreatic β cells. Treatment of MIN6 and βTC6 cells with a synthetic CB1R agonist, WIN55,212–2, led to a decrease in the expression of Bcl-2 and cyclin D2, in turn inducing cell cycle arrest in G0/G1 phase and caspase-3-dependent apoptosis. Additionally, genetic deletion and pharmacological blockade of CB1Rs after injury in mice led to increased levels of Bcl-2 and cyclin D2 in pancreatic β cells. These findings provide evidence for the involvement of Bcl-2 and cyclin D2 mediated by CB1Rs in the regulation of β-cell survival and growth, and will serve as a basis for developing new therapeutic interventions to enhance β-cell function and growth in diabetes. PMID:26967640

  20. Cannabinoids Regulate Bcl-2 and Cyclin D2 Expression in Pancreatic β Cells.

    Directory of Open Access Journals (Sweden)

    Jihye Kim

    Full Text Available Recent reports have shown that cannabinoid 1 receptors (CB1Rs are expressed in pancreatic β cells, where they induce cell death and cell cycle arrest by directly inhibiting insulin receptor activation. Here, we report that CB1Rs regulate the expression of the anti-apoptotic protein Bcl-2 and cell cycle regulator cyclin D2 in pancreatic β cells. Treatment of MIN6 and βTC6 cells with a synthetic CB1R agonist, WIN55,212-2, led to a decrease in the expression of Bcl-2 and cyclin D2, in turn inducing cell cycle arrest in G0/G1 phase and caspase-3-dependent apoptosis. Additionally, genetic deletion and pharmacological blockade of CB1Rs after injury in mice led to increased levels of Bcl-2 and cyclin D2 in pancreatic β cells. These findings provide evidence for the involvement of Bcl-2 and cyclin D2 mediated by CB1Rs in the regulation of β-cell survival and growth, and will serve as a basis for developing new therapeutic interventions to enhance β-cell function and growth in diabetes.

  1. bax, but not bcl-2, influences the prognosis of human pancreatic cancer

    OpenAIRE

    Friess, H; Lu, Z; H. Graber; Zimmermann, A.; Adler, G.; Korc, M.; Schmid, R; Buchler, M

    1998-01-01

    Background—bcl-2 and bax belong to the bcl-2-related gene family, which marks a new class of genes that influence apoptosis. The bcl-2 oncogene acts as a broad antiapoptotic factor and extends both normal and tumour cell survival. In contrast, the bax gene is a promoter of apoptosis. 
Aims—To analyse the expression of bcl-2 and bax in pancreatic cancer and correlate the results with clinical parameters. 
Patients—Pancreatic cancer tissue samples were obtained fro...

  2. Bcl-2/adenovirus E1B 19 kDa interacting protein-3 knockdown enables growth of breast cancer metastases in the lung, liver, and bone.

    Science.gov (United States)

    Manka, David; Spicer, Zachary; Millhorn, David E

    2005-12-15

    The mouse breast cancer cell lines 4T1, 4T07, and 67NR are highly tumorigenic but vary in metastatic potential: 4T1 widely disseminates, resulting in secondary tumors in the lung, liver, bone, and brain; 4T07 spreads to the lung and liver but is unable to establish metastatic nodules; 67NR is unable to metastasize. The Bcl-2/adenovirus E1B 19 kDa interacting protein-3 (Bnip-3) was recently shown to be absent after hypoxia in pancreatic cancer cell lines whereas its overexpression restored hypoxia-induced cell death. We found that Bnip-3 expression increased after 6 hours of hypoxia in all cell lines tested but was highest in the nonmetastatic 67NR cells and lowest in the highly metastatic 4T1 cells. Hypoxia-induced expression of Bnip-3 in the disseminating but nonmetastatic 4T07 cells was intermediate compared with 4T1 and 67NR cells. Cleaved caspase-3, a key downstream effector of cell death, increased after 6 hours of hypoxia in the 67NR and 4T07 cells by 1.9- and 2.5-fold, respectively. Conversely, cleaved caspase-3 decreased by 45% in the highly metastatic 4T1 cells after hypoxia. Small interfering RNA oligonucleotides targeting endogenous Bnip-3 blocked cell death and increased clonigenic survival after hypoxic challenge in vitro and increased primary tumor size and enabled metastasis to the lung, liver, and sternum of mice inoculated with 4T07 cells in vivo. These data inversely correlate the hypoxia-induced expression of the cell death protein Bnip-3 to metastatic potential and suggest that loss of Bnip-3 expression is critical for malignant and metastatic evasion of hypoxia-induced cell death. PMID:16357180

  3. Autophagy Regulates the Post-Translational Cleavage of BCL-2 and Promotes Neuronal Survival

    Directory of Open Access Journals (Sweden)

    Laura Lossi

    2010-01-01

    Full Text Available B-cell lymphoma 2 protein (BCL-2 is one of the more widely investigated anti-apoptotic protein in mammals, and its levels are critical for protecting from programmed cell death. We report here that the cellular content of BCL-2 is regulated at post-translational level along the autophagy/lysosome pathways in organotypic cultures of post-natal mouse cerebellar cortex. Specifically this mechanism appears to be effective in the cerebellar granule cells (CGCs that are known to undergo massive programmed cell death (apoptosis during post-natal maturation. By the use of specific agonists/antagonist of calcium channels at the endoplasmic reticulum it was possible to understand the pivotal role of calcium release from intracellular stores in CGC neuroprotection. The more general significance of these findings is supported by a very recent study Niemann-Pick transgenic mice.

  4. 苯扎贝特对ox-LDL诱导内皮细胞凋亡基因Bcl-2/Bax的影响%Effects of bezafibrate on apoptosis gene Bcl-2/Bax in cultured endothelial cells induced by ox-LDL

    Institute of Scientific and Technical Information of China (English)

    申晓彧; 薛丽霞; 屈巧芳; 曾秋棠

    2008-01-01

    目的 观察苯扎贝特对氧化型低密度脂蛋白(ox-LDL)诱导人脐静脉内皮细胞凋亡基因Bcl-2/Bax的影响. 方法 体外培养人脐静脉内皮细胞(HUVECs),根据实验要求分为正常对照组、ox-LDL组、低浓度苯扎贝特(50μmol/L)组、中浓度苯扎贝特(100 μmol/L)组、高浓度苯扎贝特(200μmol/L)组.RT-PCR观察各组凋亡基因Bcl-2、Bax及Bd-2/BaxmRNA的变化. 结果 与正常对照组比较,ox-LDL组凋亡基因Bcl-2表达下降(P<0.05),凋亡基因Bax表达增加(P<0.05),Bcl-2/Bax比值下降(P<0.05);不同浓度苯扎贝特组与ox-LDL组比较,Bcl-2表达增加(P<0.05),Bax表达降低(P<0.05),Bcl-2/Bax上调(P<0.05),且呈浓度效应依赖关系. 结论 ox-LDL可引起内皮细胞抗凋亡基因Bcl-2表达下调,凋亡基因Bax表达上调,Bcl-2和Bax比值下降,从而引起内皮细胞凋亡增加;苯扎贝特可通过上调Bcl-2与Bax的比值抑制ox-LDL引起的内皮细胞凋亡,起到抗动脉粥样硬化作用.

  5. Bcl-2 expression and triple negative profile in breast carcinoma.

    Science.gov (United States)

    Kallel-Bayoudh, Imen; Hassen, Hanen Ben; Khabir, Abdelmajid; Boujelbene, Noureddine; Daoud, Jamel; Frikha, Mounir; Sallemi-Boudawara, Tahia; Aifa, Sami; Rebaï, Ahmed

    2011-12-01

    Many biomarkers for breast cancer prognosis have been proposed during the last two decades, among which HER2 and oestrogen receptors are of common use in routine clinical practice. However, in recent years, BCL2 has been recognized as an important prognostic parameter in human breast cancer, although its clinical utility is well established. The aim of this study was to examine the protein expression patterns of BCL2, HER2, oestrogen (ER) and progesterone receptors (PR) and to evaluate their correlation with survival and other prognostic parameters such as tumour size, histological grade and metastasis. We used a retrospective study including 84 Tunisian women with breast cancer. Immunohistochemistry was used to measure protein expression levels of several biomarkers. Association with conventional biopathological factors was analysed by SPSS (version13). The expression rates of BCL2, HER2, ER and PR were, respectively, 69, 62, 58.3 and 51.2%. In univariate analyses, BCL2 was highly correlated with both PR (P < 0.001) and ER (P = 0.006) and also with HER2 expression (P = 0.001). The triple negative profile showed a significant association with SBR (P = 0.016) and BCL2 expression (P = 0.02). In multivariate analyses, a significant association was maintained between BCL2 and both PR and ER (P = 0.02 and P = 0.004, respectively). Survival analysis showed that BCL2 expression was positively correlated with patients survival (P = 0.032). A Bayesian network analysis of all the variables confirmed the high value of BCL2 expression as a predictor of survival. As conclusion, BCL2 expression seems to be a very useful factor that should be in combination with HER2 and ER in breast cancer prognosis. PMID:20890735

  6. Pan-Bcl-2 inhibitor obatoclax delays cell cycle progression and blocks migration of colorectal cancer cells.

    Directory of Open Access Journals (Sweden)

    Bruno Christian Koehler

    Full Text Available Despite the fact that new treatment regimes have improved overall survival of patients challenged by colorectal cancer (CRC, prognosis in the metastatic situation is still restricted. The Bcl-2 family of proteins has been identified as promising anti cancer drug target. Even though small molecules targeting Bcl-2 proteins are in clinical trials, little is known regarding their effects on CRC. The aim of this study was to preclinically investigate the value of ABT-737 and Obatoclax as anticancer drugs for CRC treatment. The effects of the BH3-mimetics ABT-737 and Obatoclax on CRC cells were assessed using viability and apoptosis assays. Wound healing migration and boyden chamber invasion assays were applied. 3-dimensional cell cultures were used for long term assessment of invasion and proliferation. Clinically relevant concentrations of pan-Bcl-2 inhibitor Obatoclax did not induce cell death. In contrast, the BH3-mimetic ABT-737 induced apoptosis in a dose dependent manner. Obatoclax caused a cell line specific slowdown of CRC cell growth. Furthermore, Obatoclax, but not ABT-737, recovered E-Cadherin expression and led to impaired migration and invasion of CRC cells. The proliferative capacity and invasiveness of CRC cells was strikingly inhibited by low dose Obatoclax in long term 3-dimensional cell cultures. Obatoclax, but not ABT-737, caused a G1-phase arrest accompanied by a downregulation of Cyclin D1 and upregulation of p27 and p21. Overexpression of Mcl-1, Bcl-xL or Bcl-2 reversed the inhibitory effect of Obatoclax on migration but failed to restore the proliferative capacity of Obatoclax-treated CRC cells. The data presented indicate broad and multifaceted antitumor effects of the pan-Bcl-2 inhibitor Obatoclax on CRC cells. In contrast to ABT-737, Obatoclax inhibited migration, invasion and proliferation in sublethal doses. In summary, this study recommends pan-Bcl-2 inhibition as a promising approach for clinical trials in CRC.

  7. A novel inhibitory mechanism of mitochondrion-dependent apoptosis by a herpesviral protein.

    Directory of Open Access Journals (Sweden)

    Pinghui Feng

    2007-12-01

    Full Text Available Upon viral infection, cells undergo apoptosis as a defense against viral replication. Viruses, in turn, have evolved elaborate mechanisms to subvert apoptotic processes. Here, we report that a novel viral mitochondrial anti-apoptotic protein (vMAP of murine gamma-herpesvirus 68 (gammaHV-68 interacts with Bcl-2 and voltage-dependent anion channel 1 (VDAC1 in a genetically separable manner. The N-terminal region of vMAP interacted with Bcl-2, and this interaction markedly increased not only Bcl-2 recruitment to mitochondria but also its avidity for BH3-only pro-apoptotic proteins, thereby suppressing Bax mitochondrial translocation and activation. In addition, the central and C-terminal hydrophobic regions of vMAP interacted with VDAC1. Consequently, these interactions resulted in the effective inhibition of cytochrome c release, leading to the comprehensive inhibition of mitochondrion-mediated apoptosis. Finally, vMAP gene was required for efficient gammaHV-68 lytic replication in normal cells, but not in mitochondrial apoptosis-deficient cells. These results demonstrate that gammaHV-68 vMAP independently targets two important regulators of mitochondrial apoptosis-mediated intracellular innate immunity, allowing efficient viral lytic replication.

  8. Inhibitor of apoptosis proteins and apoptosis

    Institute of Scientific and Technical Information of China (English)

    Yunbo Wei; Tingjun Fan; Miaomiao Yu

    2008-01-01

    Apoptosis is a physiological cell death process that plays a critical role in development, homeostasis, and immune defense of multicellular animals. Inhibitor of apoptosis proteins (IAPs) constitute a family of proteins that possess between one and three baculovirus IAP repeats. Some of them also have a really interesting new gene finger domain, and can prevent cell death by binding and inhibiting active caspases, but are regulated by IAP antagonists. Some evidence also indicates that IAP can modulate the cell cycle and signal transduction. The three main factors, IAPs, IAP antagonists, and caspases, are involved in regulating the progress of apoptosis in many species. Many studies and assumptions have been focused on the anfractuous interactions between these three main factors to explore their real functional model in order to develop potential anticancer drugs.In this review, we describe the classification, molecular structures, and properties of IAPs and discuss the mechanisms of apoptosis. We also discuss the promising significance of clinical applications of IAPs in the diagnosis and treatment of malignancy.

  9. Safflor yellow B suppresses angiotensin II-mediated human umbilical vein cell injury via regulation of Bcl-2/p22phox expression

    International Nuclear Information System (INIS)

    Intracellular reactive oxygen species (ROS) are derived from nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. Angiotensin II (Ang II) can cause endothelial dysfunction by promoting intracellular ROS generation. Safflor yellow B (SYB) effectively inhibits ROS generation by upregulating Bcl-2 expression. In this study, we examined the effects of SYB on Ang II-induced injury to human umbilical vein endothelial cells (HUVECs), and elucidated the roles of NADPH oxidase and Bcl-2. We treated cultured HUVECs with Ang II, SYB, and Bcl-2 siRNA, and determined NADPH oxidase activity and ROS levels. Furthermore, cellular and mitochondrial physiological states were evaluated, and the expression levels of target proteins were analyzed. Ang II significantly enhanced intracellular ROS levels, caused mitochondrial membrane dysfunction, and decreased cell viability, leading to apoptosis. This was associated with increased expression of AT1R and p22phox, increased NADPH oxidase activity, and an increased ratio of Bax/Bcl-2, leading to decreases in antioxidant enzyme activities, which were further strengthened after blocking Bcl-2. Compared to Ang II treatment alone, co-treatment with SYB significantly reversed HUVEC injury. Taken together, these results demonstrate that SYB could significantly protect endothelial cells from Ang II-induced cell damage, and that it does so by upregulating Bcl-2 expression and inhibiting ROS generation. - Highlights: • Angiotensin II depresses mitochondria physiological function. • Angiotensin II activates NADPH oxidase via up-regulating expresion of p22phox. • Bcl-2 plays a pivotal role in improving mitochondria function and regulates ROS level. • Inhibitor of Bcl-2 promotes angiotensin II mediated HUVEC injury. • SYB attenuates angiotensin II mediated HUVEC injury via up regulating Bcl-2 expression

  10. Bcl-2 Regulates Reactive Oxygen Species Signaling and a Redox-Sensitive Mitochondrial Proton Leak in Mouse Pancreatic β-Cells.

    Science.gov (United States)

    Aharoni-Simon, Michal; Shumiatcher, Rose; Yeung, Anthony; Shih, Alexis Z L; Dolinsky, Vernon W; Doucette, Christine A; Luciani, Dan S

    2016-06-01

    In pancreatic β-cells, controlling the levels of reactive oxygen species (ROS) is critical to counter oxidative stress, dysfunction and death under nutrient excess. Moreover, the fine-tuning of ROS and redox balance is important in the regulation of normal β-cell physiology. We recently demonstrated that Bcl-2 and Bcl-xL, in addition to promoting survival, suppress β-cell glucose metabolism and insulin secretion. Here, we tested the hypothesis that the nonapoptotic roles of endogenous Bcl-2 extend to the regulation of β-cell ROS and redox balance. We exposed mouse islet cells and MIN6 cells to the Bcl-2/Bcl-xL antagonist Compound 6 and the Bcl-2-specific antagonist ABT-199 and evaluated ROS levels, Ca(2+) responses, respiratory control, superoxide dismutase activity and cell death. Both acute glucose stimulation and the inhibition of endogenous Bcl-2 progressively increased peroxides and stimulated superoxide dismutase activity in mouse islets. Importantly, conditional β-cell knockout of Bcl-2 amplified glucose-induced formation of peroxides. Bcl-2 antagonism also induced a mitochondrial proton leak that was prevented by the antioxidant N-acetyl-L-cysteine and, therefore, secondary to redox changes. We further established that the proton leak was independent of uncoupling protein 2 but partly mediated by the mitochondrial permeability transition pore. Acutely, inhibitor-induced peroxides promoted Ca(2+) influx, whereas under prolonged Bcl inhibition, the elevated ROS was required for induction of β-cell apoptosis. In conclusion, our data reveal that endogenous Bcl-2 modulates moment-to-moment ROS signaling and suppresses a redox-regulated mitochondrial proton leak in β-cells. These noncanonical roles of Bcl-2 may be important for β-cell function and survival under conditions of high metabolic demand. PMID:27070098

  11. Safflor yellow B suppresses angiotensin II-mediated human umbilical vein cell injury via regulation of Bcl-2/p22{sup phox} expression

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Chaoyun; He, Yanhao [School of Pharmaceutical Sciences, Binzhou Medical University, Yantai, Shandong 264003 (China); Department of Pharmacology, Xi' an Jiaotong University School of Medicine, Key Laboratory of Environment and Genes Related to Disease, Ministry of Education, Xi' an, Shaanxi 710061 (China); Yang, Ming; Sun, Hongliu; Zhang, Shuping [School of Pharmaceutical Sciences, Binzhou Medical University, Yantai, Shandong 264003 (China); Wang, Chunhua, E-mail: chunhuawang2012@163.com [School of Pharmaceutical Sciences, Binzhou Medical University, Yantai, Shandong 264003 (China)

    2013-11-15

    Intracellular reactive oxygen species (ROS) are derived from nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. Angiotensin II (Ang II) can cause endothelial dysfunction by promoting intracellular ROS generation. Safflor yellow B (SYB) effectively inhibits ROS generation by upregulating Bcl-2 expression. In this study, we examined the effects of SYB on Ang II-induced injury to human umbilical vein endothelial cells (HUVECs), and elucidated the roles of NADPH oxidase and Bcl-2. We treated cultured HUVECs with Ang II, SYB, and Bcl-2 siRNA, and determined NADPH oxidase activity and ROS levels. Furthermore, cellular and mitochondrial physiological states were evaluated, and the expression levels of target proteins were analyzed. Ang II significantly enhanced intracellular ROS levels, caused mitochondrial membrane dysfunction, and decreased cell viability, leading to apoptosis. This was associated with increased expression of AT1R and p22{sup phox}, increased NADPH oxidase activity, and an increased ratio of Bax/Bcl-2, leading to decreases in antioxidant enzyme activities, which were further strengthened after blocking Bcl-2. Compared to Ang II treatment alone, co-treatment with SYB significantly reversed HUVEC injury. Taken together, these results demonstrate that SYB could significantly protect endothelial cells from Ang II-induced cell damage, and that it does so by upregulating Bcl-2 expression and inhibiting ROS generation. - Highlights: • Angiotensin II depresses mitochondria physiological function. • Angiotensin II activates NADPH oxidase via up-regulating expresion of p22{sup phox}. • Bcl-2 plays a pivotal role in improving mitochondria function and regulates ROS level. • Inhibitor of Bcl-2 promotes angiotensin II mediated HUVEC injury. • SYB attenuates angiotensin II mediated HUVEC injury via up regulating Bcl-2 expression.

  12. Expression of Apoptosis Related Genes bcl-2 and p53 in Rat Brain after Exposure to +Gx in Simulated Emergent Return of Spacecraft%模拟飞船应急返回时+Gx暴露后大鼠脑细胞凋亡相关基因bcl-2、p53的表达

    Institute of Scientific and Technical Information of China (English)

    孙喜庆; 徐志鹏; 刘挺松; 吴斌; 张舒; 由广兴

    2005-01-01

    目的探讨bcl-2、p53在模拟飞船应急返回时高+Gx作用致大鼠脑细胞凋亡中的作用. 方法 40只雄性SD大鼠随机分为4组,即对照组、+15 Gx组、7 d模拟失重组、7 d模拟失重后再+15 Gx组,每组10只.大鼠在动物离心机上承受+Gx作用后,灌注取脑,固定包埋,做石腊切片.用免疫组化方法检测大鼠海马、顶叶皮层相关基因bcl-2和 p53表达的变化. 结果 +15 Gx暴露后1 d可见bcl-2表达减少,p53表达增加,在暴露后3 d改变明显;7 d模拟失重组大鼠在暴露后1 d可见bcl-2表达减少,p53表达增加;模拟失重后再+15 Gx组在暴露后1 d可见上述bcl-2、 p53表达的变化,在暴露后3 d改变最明显,变化比+15 Gx组或模拟失重组均明显. 结论 +15 Gx/180 s暴露可引起大鼠海马和顶叶皮层细胞凋亡相关基因bcl-2和p53表达的变化;7 d模拟失重可加重+Gx引起的大鼠脑组织损伤.

  13. Effect of Bcl-2 rs956572 SNP on regional gray matter volumes and cognitive function in elderly males without dementia.

    Science.gov (United States)

    Liu, Mu-En; Huang, Chu-Chung; Hwang, Jen-Ping; Yang, Albert C; Tu, Pei-Chi; Yeh, Heng-Liang; Hong, Chen-Jee; Liou, Ying-Jay; Chen, Jin-Fan; Lin, Ching-Po; Tsai, Shih-Jen

    2013-04-01

    The Bcl-2 gene is a major regulator of neural plasticity and cellular resilience. A single-nucleotide polymorphism (SNP) in the Bcl-2 gene, Bcl-2 rs956572, significantly modulates the expression of Bcl-2 protein and cellular vulnerability to apoptosis. This study investigated the association between the Bcl-2 rs956572 SNP and brain structural abnormalities in non-demented elders, and to test the relationship between neuropsychological performance and regional gray matter (GM) volumes. Our sample comprised 97 non-demented elderly men with a mean age of 80.6 ± 5.6 years (range, 65 to 92 years). Cognitive test results, magnetic resonance imaging, and genotyping of Bcl-2 rs956572 were examined for each subject. The differences in regional GM volumes between G homozygotes and A-allele carriers were tested using optimized voxel-based morphometry. Subjects with G homozygotes exhibited significantly worse performance in the language domain of the Cognitive Abilities Screening Instrument (CASI; p = 0.009). They also showed significantly smaller GM volumes in the right middle temporal gyrus (MTG) (BA 21), but larger GM volumes in the left precuneus (BA 31), right lingual gyrus (BA 18), and left superior occipital gyrus (BA 19) relative to A-allele carriers (p < 0.001). A trend toward a positive correlation between right MTG GM volumes and the language domain of CASI was also evident (r = 0.181; p = 0.081). The findings suggest that Bcl-2 rs956572 SNP may modulate cognitive function and regional GM volume in non-demented elderly men, and that this polymorphism may affect language performance through its effect on the right MTG. PMID:22198673

  14. Opposite role of Bax and BCL-2 in the anti-tumoral responses of the immune system

    International Nuclear Information System (INIS)

    The relative role of anti apoptotic (i.e. Bcl-2) or pro-apoptotic (e.g. Bax) proteins in tumor progression is still not completely understood. The rat glioma cell line A15A5 was stably transfected with human Bcl-2 and Bax transgenes and the viability of theses cell lines was analyzed in vitro and in vivo. In vitro, the transfected cell lines (huBax A15A5 and huBcl-2 A15A5) exhibited different sensitivities toward apoptotic stimuli. huBax A15A5 cells were more sensitive and huBcl-2 A15A5 cells more resistant to apoptosis than mock-transfected A15A5 cells (pCMV A15A5). However, in vivo, in syngenic rat BDIX, these cell lines behaved differently, as no tumor growth was observed with huBax A15A5 cells while huBcl-2 A15A5 cells formed large tumors. The immune system appeared to be involved in the rejection of huBax A15A5 cells since i) huBax A15A5 cells were tumorogenic in nude mice, ii) an accumulation of CD8+ T-lymphocytes was observed at the site of injection of huBax A15A5 cells and iii) BDIX rats, which had received huBax A15A5 cells developed an immune protection against pCMV A15A5 and huBcl-2 A15A5 cells. We show that the expression of Bax and Bcl-2 controls the sensitivity of the cancer cells toward the immune system. This sensitization is most likely to be due to an increase in immune induced cell death and/or the amplification of an anti tumour immune response

  15. Expression of bcl-2 oncogene in gastric precancerous lesions and its correlation with syndromes in traditional Chinese medicine

    Institute of Scientific and Technical Information of China (English)

    Ling Hu; Shao-Xian Lao; Chun-Zhi Tang

    2005-01-01

    AIM: To observe the protein and mRNA expression of bcl-2 oncogene in gastric precancerous lesions (GPL) and to analyze its correlation with syndromes in traditional Chinese medicine (TCM).METHODS: Sixty-seven patients with GPL confirmed by gastroscopy and pathology were studied, including 39 cases of moderate gastric mucosal dysplasia, 19 casesof severe gastric mucosa dysplasia, g cases of incompletecolon metaplasia. In syndrome differentiation of TCM, 17 cases belonged to the syndrome of qi and yin deficiency of the spleen and stomach complicated by qi stagnation, 21 cases belonged to the syndrome of qi and yin deficiency of the spleen and stomach complicated by stomach heat, 29 cases belonged to the syndrome of qi and yin deficiency of the spleen and stomach complicated by blood stasis. Protein and mRNA expression of bcl-2 oncogene weredetected by labeled streptavidin biotin (LSAB) immunohistochemistry and in situ hybridization respectively. RESULTS: Abnormal expression of protein and mRNA on bcl-2 oncogene was found in GPL, which increased gradually with the course of lesions. In moderate and severe gastric mucosal dysplasia and incomplete colon metaplasia, there was no difference in the expression of bcl-2 oncogene (P>0.05). In different accompanying syndromes, the expression of protein and mRNA on bcl-2 oncogene increased gradually in the following order: deficiency of both qi and yin of the spleen and stomach accompanying qi stagnation → stomach heat → blood stasis. In GPL, compared with accompanying blood stasis, there was an obvious difference in the expression of bd-2 oncogene between the syndrome of qi and yin deficiency of the spleen and stomach and accompanying stomach heat, so did accompanying qi stagnation (the level of protein: χ2 = 8.45, P<0.05; the level of mRNA: χ2 = 7.35,P<0.05).CONCLUSION: Apoptosis-associated bcl-2 oncogene is abnormally expressed in GPL, which correlates with different accompanying syndromes in TCM.

  16. Exosomes Secreted by Apoptosis-Resistant Acute Myeloid Leukemia (AML) Blasts Harbor Regulatory Network Proteins Potentially Involved in Antagonism of Apoptosis.

    Science.gov (United States)

    Wojtuszkiewicz, Anna; Schuurhuis, Gerrit J; Kessler, Floortje L; Piersma, Sander R; Knol, Jaco C; Pham, Thang V; Jansen, Gerrit; Musters, René J P; van Meerloo, Johan; Assaraf, Yehuda G; Kaspers, Gertjan J L; Zweegman, Sonja; Cloos, Jacqueline; Jimenez, Connie R

    2016-04-01

    Expression of apoptosis-regulating proteins (B-cell CLL/lymphoma 2 - BCL-2, Myeloid Cell Leukemia 1 - MCL-1, BCL-2 like 1 - BCL-X and BCL-2-associated X protein - BAX) in acute myeloid leukemia (AML) blasts at diagnosis is associated with disease-free survival. We previously found that the initially high apoptosis-resistance of AML cells decreased after therapy, while regaining high levels at relapse. Herein, we further explored this aspect of dynamic apoptosis regulation in AML. First, we showed that the intraindividualex vivoapoptosis-related profiles of normal lymphocytes and AML blasts within the bone marrow of AML patients were highly correlated. The expression values of apoptosis-regulating proteins were far beyond healthy control lymphocytes, which implicates the influence of microenvironmental factors. Second, we demonstrated that apoptosis-resistant primary AML blasts, as opposed to apoptosis-sensitive cells, were able to up-regulate BCL-2 expression in sensitive AML blasts in contact cultures (p= 0.0067 andp= 1.0, respectively). Using secretome proteomics, we identified novel proteins possibly engaged in apoptosis regulation. Intriguingly, this analysis revealed that major functional protein clusters engaged in global gene regulation, including mRNA splicing, protein translation, and chromatin remodeling, were more abundant (p= 4.01E-06) in secretomes of apoptosis-resistant AML. These findings were confirmed by subsequent extracellular vesicle proteomics. Finally, confocal-microscopy-based colocalization studies show that splicing factors-containing vesicles secreted by high AAI cells are taken up by low AAI cells. The current results constitute the first comprehensive analysis of proteins released by apoptosis-resistant and sensitive primary AML cells. Together, the data point to vesicle-mediated release of global gene regulatory protein clusters as a plausible novel mechanism of induction of apoptosis resistance. Deciphering the modes of communication

  17. Der Einfluss der Anästhetika Sevofluran und Propofol auf die Regulation der apoptoseassoziierten Proteine Bax, Bcl-2, Mdm-2 und p53 nach inkompletter zerebraler Hemisphärenischämie bei der Ratte

    OpenAIRE

    Bachl, Monika Maria

    2005-01-01

    Der Einfluss der Anästhetika Sevofluran und Propofol auf apoptoseassoziierte Proteine während zerebraler Ischämie ist bisher nicht erforscht. In der vorliegenden Studie wurden die Effekte dieser Narkotika auf die Regulation der Apoptosefaktoren Bax, Bcl-2, Mdm-2 und p53 bei 36 narkotisierten Sprague-Dawley-Ratten untersucht, bei denen eine inkomplette zerebrale Hemisphärenischämie mit anschließender Reperfusion induziert wurde. Die Apoptosefaktoren wurden mittels Immunfluoreszenz- und Western...

  18. Identification of a novel senolytic agent, navitoclax, targeting the Bcl-2 family of anti-apoptotic factors.

    Science.gov (United States)

    Zhu, Yi; Tchkonia, Tamara; Fuhrmann-Stroissnigg, Heike; Dai, Haiming M; Ling, Yuanyuan Y; Stout, Michael B; Pirtskhalava, Tamar; Giorgadze, Nino; Johnson, Kurt O; Giles, Cory B; Wren, Jonathan D; Niedernhofer, Laura J; Robbins, Paul D; Kirkland, James L

    2016-06-01

    Clearing senescent cells extends healthspan in mice. Using a hypothesis-driven bioinformatics-based approach, we recently identified pro-survival pathways in human senescent cells that contribute to their resistance to apoptosis. This led to identification of dasatinib (D) and quercetin (Q) as senolytics, agents that target some of these pathways and induce apoptosis preferentially in senescent cells. Among other pro-survival regulators identified was Bcl-xl. Here, we tested whether the Bcl-2 family inhibitors, navitoclax (N) and TW-37 (T), are senolytic. Like D and Q, N is senolytic in some, but not all types of senescent cells: N reduced viability of senescent human umbilical vein epithelial cells (HUVECs), IMR90 human lung fibroblasts, and murine embryonic fibroblasts (MEFs), but not human primary preadipocytes, consistent with our previous finding that Bcl-xl siRNA is senolytic in HUVECs, but not preadipocytes. In contrast, T had little senolytic activity. N targets Bcl-2, Bcl-xl, and Bcl-w, while T targets Bcl-2, Bcl-xl, and Mcl-1. The combination of Bcl-2, Bcl-xl, and Bcl-w siRNAs was senolytic in HUVECs and IMR90 cells, while combination of Bcl-2, Bcl-xl, and Mcl-1 siRNAs was not. Susceptibility to N correlated with patterns of Bcl-2 family member proteins in different types of human senescent cells, as has been found in predicting response of cancers to N. Thus, N is senolytic and acts in a potentially predictable cell type-restricted manner. The hypothesis-driven, bioinformatics-based approach we used to discover that dasatinib (D) and quercetin (Q) are senolytic can be extended to increase the repertoire of senolytic drugs, including additional cell type-specific senolytic agents. PMID:26711051

  19. Enhanced stability of Mcl1, a prosurvival Bcl2 relative, blunts stress-induced apoptosis, causes male sterility, and promotes tumorigenesis

    OpenAIRE

    Okamoto, Toru; Coultas, Leigh; Metcalf, Donald; van Delft, Mark F.; Glaser, Stefan P.; Takiguchi, Megumi; Strasser, Andreas; Bouillet, Philippe; Adams, Jerry M.; Huang, David C. S.

    2013-01-01

    We obtained evidence that the rapid turnover of Mcl1 has physiological significance by analyzing mice bearing a modified allele of Mcl1 that proved to encode a stabilized form of Mcl1. In cells under stresses such as protein synthesis inhibition or UV radiation, its life span was much longer than WT Mcl1. Male mice bearing only the modified allele were sterile due to excess early spermatogenesis, and the modified allele ameliorated the polycystic kidney disease arising in mice lacking prosurv...

  20. Clusterin silencing sensitizes pancreatic cancer MIA-PaCa-2 cells to gmcitabine via regulation of NF-kB/Bcl-2 signaling.

    Science.gov (United States)

    Xu, Miao; Chen, Xiumei; Han, Yanling; Ma, Chunqing; Ma, Lin; Li, Shirong

    2015-01-01

    Clusterin (CLU) is known as a multifunctional protein involved in a variety of physiological processes including lipid transport, epithelial cell differentiation, tumorigenesis, and apoptosis. Our recent study has demonstrated that knockdown of clusterin sensitizes pancreatic cancer cell lines to gmcitabine treatment. However the details of this survival mechanism remain undefined. Of the various downstream targets of CLU, we examined activation of the NF-kB transcription factor and subsequent transcriptional regulation of BCL-2 gene in pancreatic cancer cell MIA-PaCa-2. The MIA-PaCa-2 cells were transfected with an antisense oligonucleotide (ASO) against clusterin, which led to a decreased protein level of the antiapoptotic gene BCL-2. Furthermore, inhibition of CLU decreased the function of NF-kB, which is capable of transcriptional regulation of the BCL-2 gene. Inhibiting this pathway increased the apoptotic effect of gmcitabine chemotherapy. Re-activated NF-kB resulted in attenuation of ASO-induced effects, followed by the bcl-2 upregulation, and bcl-2 re-inhibition resulted in attenuation of Re-activated NF-kB -induced effects. Animals injected with ASO CLU in MIA-PaCa-2 cells combined with gmcitabine treatment had fewer tumors than gmcitabine or ASO CLU alone. These findings suggest that knockdown of CLU sensitized MIA-PaCa-2 cells to gmcitabine chemotherapy through modulating NF-Kb/bcl-2 pathway. PMID:26550158

  1. Sundew plant, a potential source of anti-inflammatory agents, selectively induces G2/M arrest and apoptosis in MCF-7 cells through upregulation of p53 and Bax/Bcl-2 ratio

    Science.gov (United States)

    Ghate, NB; Das, A; Chaudhuri, D; Panja, S; Mandal, N

    2016-01-01

    The worldwide cancer incidences are remarkable despite the advancement in cancer drug discovery field, highlighting the need for new therapies focusing on cancer cell and its microenvironment, including inflammation. Several species of Drosera (family: Droseraceae) are used in various traditional as well as homeopathic systems of medicine. Drosera burmannii Vahl. is also enlisted in French Pharmacopoeia in 1965 for the treatment of inflammatory diseases, including chronic bronchitis, asthma and whooping cough. The present study is designed to substantiate the potential of D. burmannii in in vitro anticancer activity and its relation with anti-inflammatory property. In vitro anticancer study revealed that DBME is inhibiting the proliferation of MCF-7 cells without affecting the viability of other malignant and non-malignant cells. DBME induced G2/M phase arrest and apoptosis in MCF-7 cells by suppressing the expression of cyclin A1, cyclin B1 and Cdk-1 and increasing the expression of p53, Bax/Bcl-2 ratio leading to activation of caspases and PARP degradation. Presence of caspase-8 (Z-IETD-fmk) and caspase-9 (Z-LEHD-fmk) inhibitors alone did prevent the apoptosis partially while apoptosis prevention was significantly observed when used in combination, suggesting vital role of caspases in DBME-induced apoptosis in MCF-7 cells. DBME also downregulated LPS-induced increased expression of iNOS, COX-2 and TNF-α along with suppression on intracellular ROS production that confirms the potential of DBME as anti-inflammatory extract. GCMS analysis revealed the presence of four major compounds hexadecanoic acid, tetradecanoic acid, hexadecen-1-ol, trans-9 and 1-tetradecanol along with some other fatty acid derivatives and carotenoids (Beta-doradecin) in DBME. These findings confirmed the anti-inflammatory activity of DBME, which is already listed in French Pharmacopeia in 1965. Here we have additionally reported the anti-breast cancer activity of DBME and its relation to the

  2. Sundew plant, a potential source of anti-inflammatory agents, selectively induces G2/M arrest and apoptosis in MCF-7 cells through upregulation of p53 and Bax/Bcl-2 ratio.

    Science.gov (United States)

    Ghate, N B; Das, A; Chaudhuri, D; Panja, S; Mandal, N

    2016-01-01

    The worldwide cancer incidences are remarkable despite the advancement in cancer drug discovery field, highlighting the need for new therapies focusing on cancer cell and its microenvironment, including inflammation. Several species of Drosera (family: Droseraceae) are used in various traditional as well as homeopathic systems of medicine. Drosera burmannii Vahl. is also enlisted in French Pharmacopoeia in 1965 for the treatment of inflammatory diseases, including chronic bronchitis, asthma and whooping cough. The present study is designed to substantiate the potential of D. burmannii in in vitro anticancer activity and its relation with anti-inflammatory property. In vitro anticancer study revealed that DBME is inhibiting the proliferation of MCF-7 cells without affecting the viability of other malignant and non-malignant cells. DBME induced G2/M phase arrest and apoptosis in MCF-7 cells by suppressing the expression of cyclin A1, cyclin B1 and Cdk-1 and increasing the expression of p53, Bax/Bcl-2 ratio leading to activation of caspases and PARP degradation. Presence of caspase-8 (Z-IETD-fmk) and caspase-9 (Z-LEHD-fmk) inhibitors alone did prevent the apoptosis partially while apoptosis prevention was significantly observed when used in combination, suggesting vital role of caspases in DBME-induced apoptosis in MCF-7 cells. DBME also downregulated LPS-induced increased expression of iNOS, COX-2 and TNF-α along with suppression on intracellular ROS production that confirms the potential of DBME as anti-inflammatory extract. GCMS analysis revealed the presence of four major compounds hexadecanoic acid, tetradecanoic acid, hexadecen-1-ol, trans-9 and 1-tetradecanol along with some other fatty acid derivatives and carotenoids (Beta-doradecin) in DBME. These findings confirmed the anti-inflammatory activity of DBME, which is already listed in French Pharmacopeia in 1965. Here we have additionally reported the anti-breast cancer activity of DBME and its relation to the

  3. Concomitant loss of proapoptotic BH3-only Bcl-2 antagonists Bik and Bim arrests spermatogenesis

    OpenAIRE

    Coultas, Leigh; Bouillet, Philippe; Loveland, Kate L.; Meachem, Sarah; Perlman, Harris; Adams, Jerry M.; Strasser, Andreas

    2005-01-01

    The BH3-only proteins of the Bcl-2 family initiate apoptosis through the activation of Bax-like relatives. Loss of individual BH3-only proteins can lead either to no phenotype, as in mice lacking Bik, or to marked cell excess, as in the hematopoietic compartment of animals lacking Bim. To investigate whether functional redundancy with Bim might obscure a significant role for Bik, we generated mice lacking both genes. The hematopoietic compartments of bik−/−bim−/− and bim−/− mice were indistin...

  4. Clinical significance of bax/bcl-2 ratio in chronic lymphocytic leukemia

    OpenAIRE

    Del Principe, Maria Ilaria; Bo, Michele Dal; Bittolo, Tamara; Buccisano, Francesco; Rossi, Francesca Maria; Zucchetto, Antonella; Rossi, Davide; Bomben, Riccardo; Maurillo, Luca; Cefalo, Mariagiovanna; De Santis, Giovanna; Venditti, Adriano; Gaidano, Gianluca; Amadori, Sergio; de Fabritiis, Paolo

    2016-01-01

    In chronic lymphocytic leukemia the balance between the pro-apoptotic and anti-apoptotic members of the bcl-2 family is involved in the pathogenesis, chemorefractoriness and clinical outcome. Moreover, the recently proposed anti-bcl-2 molecules, such as ABT-199, have emphasized the potential role of of bcl-2 family proteins in the context of target therapies. We investigated bax/bcl-2 ratio by flow cytometry in 502 patients and identified a cut off of 1.50 to correlate bax/bcl-2 ratio with we...

  5. Energetic heavy ions overcome tumor radioresistance caused by overexpression of Bcl-2

    International Nuclear Information System (INIS)

    Background and purpose: Overexpression of Bcl-2 is frequent in human cancers and has been associated with radioresistance. Here we investigated the potential impact of heavy ions on Bcl-2 overexpressing tumors. Materials and methods: Bcl-2 cells (Bcl-2 overexpressing HeLa cells) and Neo cells (neomycin resistant gene-expressing HeLa cells) exposed to γ-rays or heavy ions were assessed for the clonogenic survival, apoptosis and cell cycle distribution. Results: Whereas Bcl-2 cells were more resistant to γ-rays (0.2 keV/μm) and helium ions (16.2 keV/μm) than Neo cells, heavy ions (76.3-1610 keV/μm) yielded similar survival regardless of Bcl-2 overexpression. Carbon ions (108 keV/μm) decreased the difference in the apoptotic incidence between Bcl-2 and Neo cells, and prolonged G2/M arrest that occurred more extensively in Bcl-2 cells than in Neo cells. Conclusions: High-LET heavy ions overcome tumor radioresistance caused by Bcl-2 overexpression, which may be explained at least in part by the enhanced apoptotic response and prolonged G2/M arrest. Thus, heavy-ion therapy may be a promising modality for Bcl-2 overexpressing radioresistant tumors

  6. Bax to Bcl-2 ratio and Ki-67 index are useful predictors of neoadjuvant chemoradiation therapy in bladder cancer

    International Nuclear Information System (INIS)

    In this study, locally advanced bladder cancer was treated by radiation combined with cisplatin therapy and a retrospective analysis was conducted to predict the clinical response to chemoradiotherapy (CRT) based on the immunohistochemistry of apoptosis-related proteins. Sixty-two patients (median age, 68 years; range, 45-89 years) with transitional cell carcinoma of the bladder (pT1G3-pT4M0) treated with CRT (median dose: 40.5 Gy of radiation and 230 mg of cisplatin) were studied. Mucosal biopsy was performed before and after CRT. Paraffin-embedded tumor specimens were examined with TdT-mediated dUTP-biotin nick end-labeling (TUNEL) and were immunostained for Ki-67, p53, Bcl-2 and Bax; the Bax/Bcl-2 ratio and apoptosis index (AI) were calculated. Clinical features of the patients and response to CRT were compared with data obtained from examination of the tumors. The 62 patients had a median follow-up period of 34 months (range, 3-84 months). Responses to CRT were as follows: complete response (CR), 34%; partial response (PR), 45%; no change (NC), 21%. The survival rate of patients with Ki-67-positive tumors was significantly lower than those of patients with Ki-67-negative tumors (P<0.05). No significant correlation was observed between the expression of any protein, the AI and the clinical response. However, the Bax/Bcl-2 ratio showed a significant association with the CR rate (P=0.0289). The results of this study suggest that the combined assessment of Bcl-2 and Bax protein expression may be used to predict a clinical response to CRT based on the Bax/Bcl-2 ratio determined before therapy. The Ki-67 index may be a useful predictor of prognosis in patients treated by CRT. (author)

  7. Significance of Bcl-2 family in tumor progression and therapy%Bcl-2家族在肿瘤进展和治疗中的意义

    Institute of Scientific and Technical Information of China (English)

    朱园园

    2008-01-01

    Bcl-2 family have dual-regulating effects on cell apoptosis mediated by mitoehondrion. The ratio of pro-apoptosis members and anti-apoptosis members closely correlates with tumorigenesis, drug-resist-ance and prognosis. Therefore,Bcl-2 family become important targets in tumor biotherapy. Many strategies have been applied to tumors treatment targeting Bcl-2 family,such as some biological treatment,short peptides and organic small molecules.%Bcl-2家族对于线粒体途径细胞凋亡具有双重调控作用,其促凋亡蛋白与抑凋亡蛋白的比例与肿瘤形成、肿瘤耐药性的产生及预后密切相关.因此,Bcl-2家族成为肿瘤生物治疗中的重要靶点,针对Bcl-2家族的某些生物治疗手段和短肽、有机小分子等新药被开发应用于Bcl-2高表达肿瘤的治疗.

  8. Bcl-2 and bax expression and prostate cancer outcome in men treated with radiotherapy in Radiation Therapy Oncology Group protocol 86-10

    International Nuclear Information System (INIS)

    Purpose: Bcl-2 and bax are proteins with opposing roles in apoptosis regulation; yet abnormal expression of either has been associated with failure after radiotherapy (RT). In this study we examined bcl-2 and bax expression as predictive markers in men treated with radiotherapy ± androgen deprivation on Radiation Therapy Oncology Group (RTOG) protocol 86-10. Experimental Design: Suitable archival diagnostic tissue was obtained from 119 (26%) patients for bcl-2 analysis and 104 (23%) patients for bax analysis. Cox proportional hazards multivariate analysis was used to determine the relationship of abnormal bcl-2 and bax expression to the end points of local failure, distant metastasis, cause-specific mortality, and overall mortality. Bcl-2 overexpression was classified as any tumor cell cytoplasmic staining and altered bax expression was classified as greater or lesser cytoplasmic staining intensity of tumor cells as compared with adjacent normal prostate epithelium. Results: The study cohort exhibited bcl-2 overexpression in 26% (n = 30) of cases and abnormal bax expression in 47% (n = 49) of cases. A borderline significant relationship was observed between abnormal bax expression and higher Gleason score (p = 0.08). In univariate and multivariate analyses, there was no statistically significant relationship seen between abnormal bcl-2 or bax expression and outcome. Conclusions: Abnormal bcl-2 and bax expression were not related to any of the end points tested. The cohort examined was comprised of patients with locally advanced disease and it is possible that these markers may be of greater value in men with earlier-stage prostate cancer

  9. Different Expressions of HIF-1α, Bcl-2 and Baxin DU145 Prostate Cancer Cells Transplanted in Nude Mouse between X-Ray and Neutron Irradiation

    International Nuclear Information System (INIS)

    To investigate the radiobiologic effects of neutron and X-ray irradiation on DU-145 prostate carcinoma cells by identifying the differences of HIF-1α expression and apoptosis. Nude mice were injected with the human prostate cancer cell line, DU-145, and then irradiated with 2 Gy and 10 Gy X-rays, or 0.6 Gy and 3.3 Gy neutrons, respectively. The mice were sacrificed at 24 hours and 120 hours after irradiation. The expression levels of HIF-1α, Bcl-2 and Bax were compared with immunohistochemical staining and western blotting. The apoptotic indexes were compared with the Terminal deoxynucleotidyl biotin-dUTP nick and labeling (TUNEL) assay. At day 1, HIF-1α and Bcl-2 expression decreased, while Bax expression and the number of TUNEL positive cells increased in neutron irradiated groups for the control and X-ray irradiated groups. The Bcl-2/Bax ratio was significantly lower in the neutron irradiated groups regardless of dose (p=0.001). The same pattern of the differences in the expressions of the HIF-1α, Bcl-2, Bax, Bcl-2/Bax ratio, and apoptotic indexes were indentified at day 5. HIF-1α expression was related with Bcl-2 (p=0.031), Bax (p=0.037) expressions and the apoptotic indexes (p=0.016) at day 5. Neutron irradiation showed a decrease in HIF-1α, Bcl-2 expression, and Bcl-2/Bax ratio, but increased Bax expression regardless of dose. This study suggests that the differences radiobiological responses between photon and neutron irradiation may be related to different HIF-1α expression and subsequent apoptotic protein expressions

  10. Increase in Bcl2 expression of penile and prostate cells of Sprague Dawley male rats following treatment with buceng (combination of Pimpinella alpina molk with Eurycoma longifolia Jack

    Directory of Open Access Journals (Sweden)

    Taufiqurrachman Nasihun

    2015-04-01

    Full Text Available Background: Treatment with buceng combination of Eurycoma longifolia Jack and Pimpinella alpine Molk has been proven to increase testosterone level, decrease apoptosis and caspase3 expression. Bcl2 is an antiapoptotic protein found in cytoplasm which inhibits cells apoptosis. This study was aimed to investigate the effect of buceng on Bcl2 expression on penile and prostate tissues of the rats. Methods: In this experimental study, 24 male Sprague Dawley rats of 90 days old, weighing ± 300 grams, were randomly assigned into four groups. Group A, normal rats. Group B, castrated rats and treated with buceng 100 mg/day, per oral (Cast-Bcg; Group C, castrated rats and treated with 2 ml of water as placebo against buceng (Cast-Plac. Group D, castrated rats, treated with mesterolone 6.75 mg/day, per oral, as exogenous testosterone (Cast-Mest. All rats were treated for 30 days. Manova test was used to analyze the different expression of Bcl2 among groups with significance level at p ≤ 0.05. Results: Castration was associated with significant decrease of Bcl2 expression in the penile and prostate tissues (53.0 and 50.9%, respectively compared to normal rats (82.6 and 84.2%, respectively, p < 0.001. Treatment with mesterolone reversed Bcl2 expression (77.1 and 78.1% to a near normal level. The same level of Bcl2 expression was also observed with buceng treatment (73.8 and 78.2%.Conclusion: The treatment with buceng could enhance Bcl2 expression in penile and prostate tissues, comparable to normal rats and mesterolone treated rats.

  11. Clinical significance of bax/bcl-2 ratio in chronic lymphocytic leukemia.

    Science.gov (United States)

    Del Principe, Maria Ilaria; Dal Bo, Michele; Bittolo, Tamara; Buccisano, Francesco; Rossi, Francesca Maria; Zucchetto, Antonella; Rossi, Davide; Bomben, Riccardo; Maurillo, Luca; Cefalo, Mariagiovanna; De Santis, Giovanna; Venditti, Adriano; Gaidano, Gianluca; Amadori, Sergio; de Fabritiis, Paolo; Gattei, Valter; Del Poeta, Giovanni

    2016-01-01

    In chronic lymphocytic leukemia the balance between the pro-apoptotic and anti-apoptotic members of the bcl-2 family is involved in the pathogenesis, chemorefractoriness and clinical outcome. Moreover, the recently proposed anti-bcl-2 molecules, such as ABT-199, have emphasized the potential role of of bcl-2 family proteins in the context of target therapies. We investigated bax/bcl-2 ratio by flow cytometry in 502 patients and identified a cut off of 1.50 to correlate bax/bcl-2 ratio with well-established clinical and biological prognosticators. Bax/bcl-2 was 1.50 or over in 263 patients (52%) with chronic lymphocytic leukemia. Higher bax/bcl-2 was associated with low Rai stage, lymphocyte doubling time over 12 months, beta-2 microglobulin less than 2.2 mg/dL, soluble CD23 less than 70 U/mL and a low risk cytogenetic profile (Pbax/bcl-2 was correlated with unmutated IGHV (Pbax/bcl-2 (Pbax/bcl-2 identified cases with significant longer PFS (P=0.00002 and P=0.039). In multivariate analysis of progression-free survival and overall survival, bax/bcl-2 was an independent prognostic factor (P=0.0002 and P=0.002). In conclusion, we defined the prognostic power of bax/bcl-2 ratio, as determined by a flow cytometric approach, and highlighted a correlation with chemoresistance and outcome in chronic lymphocytic leukemia. Finally, the recently proposed new therapies employing bcl-2 inhibitors prompted the potential use of bax/bcl-2 ratio to identify patients putatively resistant to these molecules. PMID:26565002

  12. Immunohistochemical study of cell proliferation, Bcl-2, p53, and caspase-3 expression on preneoplastic changes induced by cadmium and zinc chloride in the ventral rat prostate.

    OpenAIRE

    Arriazu, Riánsares; José M Pozuelo; Henriques-Gil, Nuno; Perucho, Teresa; Martín, Rocío; Rodríguez, Rosario; Santamaría, Luis

    2006-01-01

    KEYWORDS CLASSIFICATION: Animals;Apoptosis;biosynthesis;Biology;chemically induced;Cadmium;Cadmium Chloride;Carcinogens;Caspase 3;Caspases;Cell Proliferation;Chlorides;Immunohistochemistry;metabolism;Male;mechanisms of carcinogenesis;pathology;pharmacology;Precancerous Conditions;Proliferating Cell Nuclear Antigen;Prostate;Prostatic Intraepithelial Neoplasia;Prostatic Neoplasms;Proteins;Proto-Oncogene Proteins;Proto-Oncogene Proteins c-bcl-2;Rats;Rats,Sprague-Dawley;Research;Spain;toxicity;Ti...

  13. bcl-2 expression is not associated with survival in metastatic cutaneous melanoma: A historical cohort study

    OpenAIRE

    Corleta Oly C; Espíndola Marília B

    2008-01-01

    Abstract Background Programmed cell death (apoptosis) has been implicated in tumor development and may affect the metastatic potential of tumor cells. The role of bcl-2, a proto-oncogene that inhibits apoptosis, has been studied in several malignancies, including cutaneous melanoma (CM). The purpose of this study was to evaluate the immunohistochemical expression of bcl-2 in 35 regional lymph node, 28 subcutaneous and 17 visceral CM metastases, correlating the findings with patient survival. ...

  14. BAX/BCL-2 mRNA and protein expression in human breast MCF-7 cells exposed to drug vehicles-methanol and dimethyl sulfoxide (DMSO for 24 hrs

    Directory of Open Access Journals (Sweden)

    Gbenga Anthony Adefolaju

    2015-01-01

    Full Text Available Background: Methanol and DMSO are commonly used as carrier solvents for lipophilic chemicals in in-vitro experiments. However, very little information is available regarding the effects of these solvents on the expression of pro and anti-apoptotic genes and proteins. Materials and Methods: In this study, we examined the cytotoxic effects of methanol and dimethylsulfoxide at 0.5% (final concentrations recommended for in-vitro toxicity assays on human breast cancer MCF-7 cells. We also investigated the effects of these solvents on the mRNA and immunocytochemical expression of apoptotic proteins BAX and BCL-2. Results: The results of neutral red cell viability assay showed that methanol and DMSO concentrations of 0.5% exhibited no cytotoxic effects on MCF-7 cells following a 24 hour exposure. Gene expression and Immunofluorescence results showed that methanol but not DMSO reduced the expression of the BAX pro-apoptotic protein, while both solvents did not alter the expression of the BCL-2 oncoprotein. Conclusion: Our results suggest that while methanol concentrations at 0.5% may be appropriate for in vitro toxicity studies in human breast cancer MCF-7 cells, it could alter the results of gene and protein expression experiments.

  15. The effect of radiation on bcl-2 and bax in hyperplastic prostatic tissues

    International Nuclear Information System (INIS)

    Aim: To investigate the expressions of bcl-2 and bax in benign prostatic hyperplasia (BPH) and the effect of β-rays on bcl-2 and bax. Methods: The expressions of bcl-2 and bax are studied by means of immunohistochemical method in 9 normal prostate (NP) and 15 BPH and 35 patients treated with 90Sr/90Y Prostatic Hyperplasia Applicator. Results: The expressions of bcl-2 in epithelia of NP and BPH are higher than that in stroma P<0.01=. The expressions of bcl-2 in epithelia and stroma of BPH are higher than that in NP P<0.01=. The expressions of bax in epithelia of NP are higher than that in BPH P<0.05=. However ,the expressions of bcl-2 in epithelia and stroma of BPH are higher than bax P<0.01 =. Compared with the control group, the expressions of bcl-2 in epithelia and stroma of BPH treated with 90Sr/90Y Prostatic Hyperplasia Applicator decreased and the expressions of bax increased P<0.01=. Conclusion: bcl-2 gene and bax gene play an important role in the regulation of prostatic apoptosis and the treatment of β-rays can accelerate the apoptosis of prostatic tissues. (authors)

  16. Influences of HIF-lα on Bax/Bcl-2 and VEGF expressions in rats with spinal cord injury

    OpenAIRE

    Chen, Mao-Hua; Ren, Qing-Xian; Yang, Wen-Fa; Chen, Xiang-Lin; Lu, Chuan; Sun, Jun

    2013-01-01

    Hypoxia-inducible factor 1-alpha (HIF-1α) is a subunit of HIF-l and thought to be able to protect hypoxic cells from apoptosis or necrosis under ischemic and anoxic conditions. This study aimed to investigated whether recombinant adenovirus vector over-expressing HIF-lα could affect apoptosis-related proteins (Bcl-2 and Bax) and vascular endothelial growth factor (VEGF) in a rat spinal cord injury (SCI) model. A total of 60 male SD rats were divided into 4 groups: Sham, Control, Ad-Blank and ...

  17. Proteasomal Degradation of Human Peptidyl Prolyl Isomerase Pin1-pointing Phospho Bcl2 toward Dephosphorylation

    Directory of Open Access Journals (Sweden)

    Aruna Basu

    2002-01-01

    Full Text Available Microtubule inhibitor-induced Bcl2 phosphorylation is detrimental to its antiapoptotic function. Phosphorylation of Bcl2 predominantly occurs on two serine residues (70 and 87 in cells arrested at G2-M phase by microtubule disarraying agents. Phospho Bcl2 can associate with a cis-trans peptidyl prolyl isomerase, Pini. Pini and its homologues are known to target the proline residue carboxyl terminal to the phosphorylated threonine or serine residue of mitotic phosphoproteins, such as Bcl2. However, it was not clear how an extranuclear protein could associate with nuclear Pini. The confocal images of the immunofluorescence studies employing phospho Bcl2-specific antibody developed in the laboratory demonstrated the translocation of phospho Bcl2 inside the nucleus. Interestingly, proteasomal degradation of Pini facilitates dephosphorylation of phospho Bcl2 due to longer exposure of Taxol. Here we show for the first time that proteasomal degradation of Pini is the key factor to determine the fate of phosphoforms of Bcl2. When Pini is degraded by proteasomes, phospho Bcl2 is converted to its native form. Thus, transient conformational change of Bcl2 due to association with peptidyl prolyl isomerase can contribute to irreversible apoptotic signaling.

  18. Bcl-2 associated with severity of manic symptoms in bipolar patients in a manic phase.

    Science.gov (United States)

    Chen, Wei-Ting; Huang, Tiao-Lai; Tsai, Meng-Chang

    2015-02-28

    B cell lymphoma protein-2 (Bcl-2) may contribute to the pathophysiology of bipolar disorder, and may be involved in the therapeutic action of anti-manic drugs. The aim of this study was to investigate serum levels of Bcl-2 in bipolar patients in a manic phase, and evaluate the Bcl-2 changes after treatment. We consecutively enrolled 23 bipolar inpatients in a manic phase and 40 healthy subjects; 20 bipolar patients were followed up with treatment. Serum Bcl-2 levels were measured with assay kits. All 20 patients were evaluated by examining the correlation between Bcl-2 levels and Young Mania Rating Scale (YMRS) scores, using Spearman׳s correlation coefficients. The serum Bcl-2 levels in bipolar patients in a manic phase were higher than in healthy subjects, but without a significant difference. The YMRS scores were significantly negatively associated with serum Bcl-2 levels (p=0.042). Bcl-2 levels of the 20 bipolar patients were measured at the end of treatment. Using the Wilcoxon Signed Rank test, we found no significant difference in the Bcl-2 levels of bipolar patients after treatment. Our results suggest that Bcl-2 levels might be an indicator of severity of manic symptoms in bipolar patients in a manic phase. PMID:25563670

  19. Expression of Bcl-2 and NF-κB in brain tissue after acute renal ischemia-reperfusion in rats

    Institute of Scientific and Technical Information of China (English)

    Na Zhang; Gen-Yang Cheng; Xian-Zhi Liu; Feng-Jiang Zhang

    2014-01-01

    Objective:To investigate the effect of acute renal ischemia reperfusion on brain tissue. Methods:Fourty eight rats were randomly divided into four groups(n=12): sham operation group,30 min ischemia60 min reperfusion group,60 min ischemia60 min reperfusion group, and 120 min ischemia60 min reperfusion group.The brain tissues were taken after the experiment. TUNEL assay was used to detect the brain cell apoptosis, and western blot was used to detect the expression of apoptosis-related proteins and inflammatory factors.Results:Renal ischemia-reperfusion induced apoptosis of brain tissues, and the apoptosis increased with prolongation of ischemia time.The detection at the molecular level showed decreasedBcl-2 expression, increasedBax expression, upregulated expression ofNF-κB and its downstream factor COX-2/PGE2.Conclusions:Acute renal ischemia-reperfusion can cause brain tissue damage, manifested as induced brain tissues apoptosis and inflammation activation.

  20. Expression of Bcl2 proto-oncogene in primary tumors of the central nervous system.

    Directory of Open Access Journals (Sweden)

    Tyagi D

    2002-07-01

    Full Text Available The present study was addressed to find out the expression of Bcl2 proto-oncogene in tumor tissues derived from 25 patients with primary central nervous system tumors. Brain parenchyma in 8 cases, with deeply located tumor, was also examined for Bcl2 expression which served as control. Both benign and malignant tumors (confirmed by histopathological examination expressed Bcl2 gene product. Tumors exhibited 2-6 fold increase in Bcl2 expression as compared to the normal parenchyma adjacent to some of these tumors studied. However, no correlation was found between the histopathological types of tumor, glial fibrillary acidic protein positivity and degree of Bcl2 expression. Based on this study, we propose that the overexpression of Bcl2 gene product found in primary CNS tumors may be an important molecular event which is known to make the various types of tumor resistant to chemotherapy or radiotherapy.

  1. Kinetics of radiation-induced apoptosis in neonatal urogenital tissues with and without protein synthesis inhibition

    International Nuclear Information System (INIS)

    The difference in incidence of radiation-induced apoptosis between two neonatal urogenital tissues, kidney and testis, was analysed over a 24h period. Concurrent administration of cycloheximide (10mg/kg body weight), a protein synthesis inhibitor, with radiation treatment was used to determine whether new protein synthesis had a role in induction of apoptosis in this in vivo model. Many chemotherapeutic drugs act via protein synthesis inhibition, and we believe that the results of this latter analysis may provide information for the planning of concurrent radio and chemotherapy. Apoptosis was quantified using morphological parameters, and verified by DNA gel electrophoresis for the typical banding pattern, and by electron microscopy. The proliferative index in tissues was studied, using [6-3H]-thymidine uptake ( 1h prior to euthanasia and collection of tissues) and autoradiography as indicators of cell proliferation (S-phase). Tissue was collected 2, 4, 6, 8, and 24h after radiation treatment. Expression of one of the apoptosis-associated genes, Bcl-2 (an apoptosis inhibitor/cell survival gene), was studied using immunohistochemistry. Apoptosis peaked at 4h in the testis and 6h in the kidney, emphasising the necessity of knowing tissue differences in radiation response if comparing changes at a particular time. A higher proportion (almost five fold) of the apoptotic cells died in S-phase in the kidney than the testis, over the 24h. Protein synthesis inhibition completely negated induction of apoptosis in both tissues. Necrosis was not identified at any time. Cycloheximide treatment greatly diminished Bcl-2 expression. The differences in response of the two tissues to irradiation relates to their innate cell (genetic) controls, which may be determined by their state of differentiation at time of treatment, or the tissue type. This in vivo study also suggests the model may be useful for analysis of other cancer therapies for example polychemotherapies or chemo

  2. Kinetics of radiation-induced apoptosis in neonatal urogenital tissues with and without protein synthesis inhibition

    Energy Technology Data Exchange (ETDEWEB)

    Gobe, G.C.; Harmon, B.; Schoch, E.; Allan, D.J. [Queensland Univ., St. Lucia, QLD (Australia). Dept. of Chemistry

    1996-12-31

    The difference in incidence of radiation-induced apoptosis between two neonatal urogenital tissues, kidney and testis, was analysed over a 24h period. Concurrent administration of cycloheximide (10mg/kg body weight), a protein synthesis inhibitor, with radiation treatment was used to determine whether new protein synthesis had a role in induction of apoptosis in this in vivo model. Many chemotherapeutic drugs act via protein synthesis inhibition, and we believe that the results of this latter analysis may provide information for the planning of concurrent radio and chemotherapy. Apoptosis was quantified using morphological parameters, and verified by DNA gel electrophoresis for the typical banding pattern, and by electron microscopy. The proliferative index in tissues was studied, using [6-{sup 3}H]-thymidine uptake ( 1h prior to euthanasia and collection of tissues) and autoradiography as indicators of cell proliferation (S-phase). Tissue was collected 2, 4, 6, 8, and 24h after radiation treatment. Expression of one of the apoptosis-associated genes, Bcl-2 (an apoptosis inhibitor/cell survival gene), was studied using immunohistochemistry. Apoptosis peaked at 4h in the testis and 6h in the kidney, emphasising the necessity of knowing tissue differences in radiation response if comparing changes at a particular time. A higher proportion (almost five fold) of the apoptotic cells died in S-phase in the kidney than the testis, over the 24h. Protein synthesis inhibition completely negated induction of apoptosis in both tissues. Necrosis was not identified at any time. Cycloheximide treatment greatly diminished Bcl-2 expression. The differences in response of the two tissues to irradiation relates to their innate cell (genetic) controls, which may be determined by their state of differentiation at time of treatment, or the tissue type. This in vivo study also suggests the model may be useful for analysis of other cancer therapies for example polychemotherapies or chemo

  3. Targeting TRPM2 Channels Impairs Radiation-Induced Cell Cycle Arrest and Fosters Cell Death of T Cell Leukemia Cells in a Bcl-2-Dependent Manner

    Directory of Open Access Journals (Sweden)

    Dominik Klumpp

    2016-01-01

    Full Text Available Messenger RNA data of lymphohematopoietic cancer lines suggest a correlation between expression of the cation channel TRPM2 and the antiapoptotic protein Bcl-2. The latter is overexpressed in various tumor entities and mediates therapy resistance. Here, we analyzed the crosstalk between Bcl-2 and TRPM2 channels in T cell leukemia cells during oxidative stress as conferred by ionizing radiation (IR. To this end, the effects of TRPM2 inhibition or knock-down on plasma membrane currents, Ca2+ signaling, mitochondrial superoxide anion formation, and cell cycle progression were compared between irradiated (0–10 Gy Bcl-2-overexpressing and empty vector-transfected Jurkat cells. As a result, IR stimulated a TRPM2-mediated Ca2+-entry, which was higher in Bcl-2-overexpressing than in control cells and which contributed to IR-induced G2/M cell cycle arrest. TRPM2 inhibition induced a release from G2/M arrest resulting in cell death. Collectively, this data suggests a pivotal function of TRPM2 in the DNA damage response of T cell leukemia cells. Apoptosis-resistant Bcl-2-overexpressing cells even can afford higher TRPM2 activity without risking a hazardous Ca2+-overload-induced mitochondrial superoxide anion formation.

  4. Targeting glutamine metabolism in multiple myeloma enhances BIM binding to BCL-2 eliciting synthetic lethality to venetoclax.

    Science.gov (United States)

    Bajpai, R; Matulis, S M; Wei, C; Nooka, A K; Von Hollen, H E; Lonial, S; Boise, L H; Shanmugam, M

    2016-07-28

    Multiple myeloma (MM) is a plasma cell malignancy that is largely incurable due to development of resistance to therapy-elicited cell death. Nutrients are intricately connected to maintenance of cellular viability in part by inhibition of apoptosis. We were interested to determine if examination of metabolic regulation of BCL-2 proteins may provide insight on alternative routes to engage apoptosis. MM cells are reliant on glucose and glutamine and withdrawal of either nutrient is associated with varying levels of apoptosis. We and others have demonstrated that glucose maintains levels of key resistance-promoting BCL-2 family member, myeloid cell leukemic factor 1 (MCL-1). Cells continuing to survive in the absence of glucose or glutamine were found to maintain expression of MCL-1 but importantly induce pro-apoptotic BIM expression. One potential mechanism for continued survival despite induction of BIM could be due to binding and sequestration of BIM to alternate pro-survival BCL-2 members. Our investigation revealed that cells surviving glutamine withdrawal in particular, enhance expression and binding of BIM to BCL-2, consequently sensitizing these cells to the BH3 mimetic venetoclax. Glutamine deprivation-driven sensitization to venetoclax can be reversed by metabolic supplementation with TCA cycle intermediate α-ketoglutarate. Inhibition of glucose metabolism with the GLUT4 inhibitor ritonavir elicits variable cytotoxicity in MM that is marginally enhanced with venetoclax treatment, however, targeting glutamine metabolism with 6-diazo-5-oxo-l-norleucine uniformly sensitized MM cell lines and relapse/refractory patient samples to venetoclax. Our studies reveal a potent therapeutic strategy of metabolically driven synthetic lethality involving targeting glutamine metabolism for sensitization to venetoclax in MM. PMID:26640142

  5. Silencing Bcl-2 Expression in Epithelial Cancer Cells Using “Smart” Particles

    Directory of Open Access Journals (Sweden)

    Yen-Ling Lin

    2014-09-01

    Full Text Available Short interfering RNA (siRNA targeted against anti-apoptotic Bcl-2 protein proved to knockdown its expression and trigger cancer cell death. We used degradable, pH-sensitive, comb-like [P(EAA-co-BMA-b-PNASI-g-P(HMA-co-TMAEMA] polymer to condense anti-Bcl-2 siRNA into “smart” particles, which proved to shuttle their cargo past the endosomal membrane and into the cytoplasm of HeLa and UM-SCC-17B cancer cells. HeLa and UM-SCC-17B cancer cells were treated with anti-Bcl-2 particles followed by quantifying Bcl-2 mRNA and protein levels using qRT-PCR and western blotting, respectively. “Smart” anti-Bcl-2 particles selectively suppress Bcl-2 mRNA and protein levels in HeLa cells by 50%–60% and 79%–81%, respectively. Similarly, “smart” anti-Bcl-2 particles inhibited Bcl-2 mRNA levels by 30%, 40%, and 20% upon incubation with UM-SCC-17B cancer cells for 48, 72, and 96 h, respectively. Bcl-2 protein expression in UM-SCC-17B cancer cells was inhibited by 30% after treatment for 72 h. Results show that pH-sensitive comb-like polymer complex anti-Bcl-2 siRNA forming “smart” nanoparticles that deliver their cargo into the cytoplasm of HeLa and UM-SCC-17B cancer cells causing Bcl-2 knockdown at the mRNA and protein levels.

  6. A Structural Viral Mimic of Prosurvival Bcl-2: A Pivotal Role for Sequestering Proapoptotic Bax and Bak

    Energy Technology Data Exchange (ETDEWEB)

    Kvansakul,M.; van Delft, M.; Lee, E.; Gulbis, J.; Fairlie, W.; Huang, D.; Colman, P.

    2007-01-01

    Many viruses express antiapoptotic proteins to counter host defense mechanisms that would otherwise trigger the rapid clearance of infected cells. For example, adenoviruses and some {gamma}-herpesviruses express homologs of prosurvival Bcl-2 to subvert the host's apoptotic machinery. Myxoma virus, a double-stranded DNA virus of the pox family, harbors antiapoptotic M11L, its virulence factor. Analysis of its three-dimensional structure reveals that despite lacking any primary sequence similarity to Bcl-2, it adopts a virtually identical protein fold. This allows it to associate with BH3 domains, especially those of Bax and Bak. We found that M11L acts primarily by sequestering Bax and Bak, thereby blocking the killing action of these essential cell-death mediators. These findings expand the family of protein sequences that act like Bcl-2 to block apoptosis and support the conclusion that the prosurvival action of these proteins critically depends on their ability to bind and antagonize Bax and/or Bak.

  7. Bcl-2 expression is altered with ovarian tumor progression: an immunohistochemical evaluation

    Directory of Open Access Journals (Sweden)

    Anderson Nicole S

    2009-10-01

    Full Text Available Abstract Background Ovarian cancer is the most lethal gynecologic malignancy. The ovarian tumor microenvironment is comprised of tumor cells, surrounding stroma, and circulating lymphocytes, an important component of the immune response, in tumors. Previous reports have shown that the anti-apoptotic protein Bcl-2 is overexpressed in many solid neoplasms, including ovarian cancers, and contributes to neoplastic transformation and drug-resistant disease, resulting in poor clinical outcome. Likewise, studies indicate improved clinical outcome with increased presence of lymphocytes. Therefore, we sought to examine Bcl-2 expression in normal, benign, and cancerous ovarian tissues to determine the potential relationship between epithelial and stromal Bcl-2 expression in conjunction with the presence of lymphocytes for epithelial ovarian tumor progression. Methods Ovarian tissue sections were classified as normal (n = 2, benign (n = 17 or cancerous (n = 28 and immunohistochemically stained for Bcl-2. Bcl-2 expression was assessed according to cellular localization, extent, and intensity of staining. The number of lymphocyte nests as well as the number of lymphocytes within these nests was counted. Results While Bcl-2 staining remained cytoplasmic, both percent and intensity of epithelial and stromal Bcl-2 staining decreased with tumor progression. Further, the number of lymphocyte nests dramatically increased with tumor progression. Conclusion The data suggest alterations in Bcl-2 expression and lymphocyte infiltration correlate with epithelial ovarian cancer progression. Consequently, Bcl-2 expression and lymphocyte status may be important for prognostic outcome or useful targets for therapeutic intervention.

  8. Bcl-2与IP3R相互作用调控肿瘤细胞程序性死亡的研究进展%IP3R/Bcl-2-channel complexes regulates programmed cell death

    Institute of Scientific and Technical Information of China (English)

    顾文文; 施韬; 顾一骅; 杨军

    2013-01-01

    由1,4,5-三磷酸肌醇受体(inositol 1,4,5-trisphosphate receptor,IP3R)介导的细胞内钙离子释放在细胞生理学过程中具有中枢性作用,其通道活性受到复杂信号网络的精细调节.近来有研究发现,IP3R是抗凋亡分子B细胞性淋巴瘤-2(B cell lymphoma-2,Bcl-2)家族蛋白的一个作用靶点,而抗凋亡Bcl-2蛋白作为IP3R的内源性调节分子,具有控制内质网中IP3R活性和抑制促凋亡钙信号的功能.已有研究证实,基于干扰Bcl-2家族成员与IP3R相互作用功能区域的多肽分子具有一定的抗肿瘤作用,因此,根据Bcl-2蛋白分子的结构特征及其与IP3R的相互作用机制而设计的靶向药物,已成为抗肿瘤新药的一个重要发展方向,并且部分药物已进入临床研究阶段.这些处于研发中的新药有望为慢性淋巴细胞白血病(chronic lymphocytic leukemia,CLL)等Bcl-2依赖性肿瘤的治疗及对抗Bcl-2介导的化疗放疗耐药现象带来新希望.本文旨在对上述研究的进展作一综述,以期为肿瘤细胞程序性死亡的调控机制的研究提供一些有价值的参考依据.%The Ca2+ release through IP3R (inositol 1,4,5-trisphosphate receptor) channels mediates the essential procedure of cellular functions.The process of Ca2+ release is elaborately regulated by the complex network system of signal transduction pathway.Recently,anti-apoptotic Bcl-2 proteins were reported to modulate Ca2+ gating of IP3R in ER (endoplasmic reticular) resulting in enhanced cellular bioenergetics and death resistance.Targeting Bcl-2-IP3R interaction was found to be able to induce apoptosis in vitro and in vivo.In addition,the natural or chemically synthesized compounds depending on the molecular structure of anti-apoptotic Bcl-2 proteins,have been tested in several clinical trials of chronic lymphocytic leukemia to verify their anti-tumor effect.Overall,current studies have provided some novel strategies of anti-tumor therapy involved in the

  9. Sec6/8 regulates Bcl-2 and Mcl-1, but not Bcl-xl, in malignant peripheral nerve sheath tumor cells.

    Science.gov (United States)

    Tanaka, Toshiaki; Kikuchi, Noriaki; Goto, Kaoru; Iino, Mitsuyoshi

    2016-05-01

    Sec6 and Sec8, which are components of the exocyst complex, has been concerned with various roles independent of its role in secretion, such as cell migration, invadopodia formation, cytokinesis, glucose uptake, and neural development. Given the vital roles of the exocyst complex in cellular and developmental processes, the disruption of its function may be closely related to various diseases such as cancer, diabetes, and neuronal disorders. Malignant peripheral nerve sheath tumors (MPNSTs) have high malignant potential and poor prognosis because of aggressive progression and metastasis. To date, no chemotherapeutic agents have been validated for MPNSTs treatment because how MPNSTs are resistant to chemotherapeutic agents remains unknown. This study demonstrates that combination of doxorubicin and sorafenib induces apoptosis in MPNST cells through downregulation of B cell lymphoma protein 2 (Bcl-2), Bcl-2-related protein long form of Bcl-x (Bcl-xl), and myeloid cell leukemia 1 (Mcl-1). Moreover, both Sec6 and Sec8 levels decreased after treatment with doxorubicin and sorafenib and were found to be associated with Bcl-2 and Mcl-1 expressions, but not Bcl-xl. Although Sec8 was found to be involved in the regulation of both Bcl-2 and Mcl-1 at the mRNA level, Sec6 regulated Bcl-2 at the mRNA level and the binding affinity of F-box and WD repeat domain containing 7 and Mcl-1, thereby controlling Mcl-1 at the protein level. Bcl-2 or Mcl-1 mRNA suppression by Sec6 or Sec8 depletion resulted in significant changes in nuclear factor-kappa B, cAMP response element, and p53 transcriptional activity. These results suggest that Sec6 and Sec8 are therapeutic target molecules in MPNST. PMID:26892009

  10. The anti-apoptotic members of the Bcl-2 family are attractive tumor-associated antigens

    DEFF Research Database (Denmark)

    Straten, Per thor; Andersen, Mads Hald

    2010-01-01

    Anti-apoptotic members of the Bcl-2 family (Bcl-2, Bcl-X(L) and Mcl-2) are pivotal regulators of apoptotic cell death. They are all highly overexpressed in cancers of different origin in which they enhance the survival of the cancer cells. Consequently, they represent prime candidates for anti......, spontaneous cellular immune responses against the Bcl-2 family proteins have been identified as frequent features in cancer patients underscoring that these proteins are natural targets for the immune system. Thus, Bcl-2 family may serve as an important and widely applicable target for anti......-cancer immunotherapeutic strategies, alone or in the combination with conventional therapy. Here, we summarize the current knowledge of Bcl-2 family proteins as T-cell antigens, which has set the stage for the first explorative trial using these antigens in therapeutic vaccinations against cancer, and discuss future...

  11. Expression of HER-2 in MCF-7 breast cancer cells modulates anti-apoptotic proteins Survivin and Bcl-2 via the extracellular signal-related kinase (ERK) and phosphoinositide-3 kinase (PI3K) signalling pathways

    International Nuclear Information System (INIS)

    The oncoprotein HER-2 is over-expressed and/or has undergone gene amplification in between 20 to 30% of breast and ovarian cancers. HER-2 amplified breast cancer is associated with a poor prognosis and increased resistance to chemo- and hormonal therapy. Data supporting the transforming potential of HER-2 are irrefutable but the mechanism by which HER-2 contributes to this process is complex and a unified model of HER2-induced increased cell proliferation and survival has not emerged. To understand the initial event(s) that take place by HER-2 over expression, we studied the effect of short term induction of HER-2 expression in the MCF7 breast cancer cell line. We examined the modulation of apoptotic pathways by tetracycline-regulated HER-2 expression for 48 hrs in the MCF7 breast cancer cell line. Specific inhibitors were used to determine signalling pathways that are required for HER-2 induced up-regulation of survivin. Tetracycline regulated short term over expression of HER-2 in the MCF7 cell line increased the antiapoptotic proteins Bcl-2 and survivin levels. Significant increase of extracellular signal-related kinase (ERK) activation but not AKT1, AKT2 and STAT3 was observed in HER-2 over-expressing MCF7 cells. Specific inhibitors of ERK, and phosphoinositide-3 kinase (PI3K), inhibited the HER-2 induced up-regulation of survivin. We did not observe a change in survivin and NF-κB promoter activity in HER-2 expressing MCF7 cells. Our results indicate that short term over expression of HER-2 up regulates antiapoptotic proteins Bcl-2 and survivin in MCF7 cells. We determined that survivin is up-regulated via ERK activation and PI3K signalling. Additionally we show that survivin up-regulation is not at transcriptional level. These data provide insight into the mechanism(s) by which induction of HER-2 over expression up-regulates survivin and Bcl-2 and identifies new targets for therapy of breast cancer

  12. Ganoderma lucidum spore powder modulates Bcl-2 and Bax expression in the hippocampus and cerebral cortex, and improves learning and memory in pentylenetetrazole-kindled rats

    Institute of Scientific and Technical Information of China (English)

    Shuang Zhao; Shengchang Zhang; Shuqiu Wang

    2011-01-01

    We studied the effects of Ganoderma lucidum spore powder on Bax and Bcl-2 expression and neuronal apoptosis in pentylenetetrazole-kindled epileptic rats. Sixty adult rats were randomly divided into a control group, an epileptic group (kindled) and three medication groups ( 150, 300,450 mg/kg given to kindled rats). Bax and Bcl-2 immunohistochemistry and TUNEL labeling show ed that the number of Bax- and TUNEL-positive cells in the hippocampus and cerebral cortex decreased significantly in the high-dose medication group, while the number of Bcl-2immunoreactive cells increased. The Morris water maze test showed that high-dose treatment significantly shortened escape latency and increased spatial probe trial performance. Our findings indicate that a high dose of Ganoderma lucidum spore powder upregulates the expressionof antiapoptotic Bcl-2 protein in the hippocampus and cerebral cortex, inhibits proapoptotic Bax expression, and decreases seizure-induced neuronal apoptosis. Further,Ganoderma lucidum appears to protect against epilepsy-related learning and memory impairments.

  13. Expression of Bcl-2 and Bax in extrahepatic biliary tract carcinoma and dysplasia

    Institute of Scientific and Technical Information of China (English)

    Sheng-Mian Li; Shu-Kun Yao; Nobuyoshi Yamamura; Toshitsugu Nakamura

    2003-01-01

    AIM: To compare the difference of expression of Bcl-2 and Bax in extrahepatic biliary tract carcinoma and dysplasia, and to analyze the role of Bcl-2 and Bax proteins in the progression from dysplasia to carcinoma and to evaluate the correlation of Bcl-2/Bax protein expression with the biological behaviors.METHODS: Expressions of Bcl-2 and Bax were examined immunohistochemically in 27 cases of extrahepatic biliary tract carcinomas (bile duct carcinoma: n=21, carcinoma of ampulla of Vater: n=6), and 10 cases of atypical dysplasia.Five cases of normal biliary epithelial tissues were used as controls. A semiquantitative scoring system was used to assess the Bcl-2 and Bax reactivity.RESULTS: The expression of Bd-2 was observed in 10 out of 27 (37.0 %) invasive carcinomas, 1 out of 10 clysplasias, none out of 5 normal epithelial tissues. Bax expression rate was 74.1% (20/27) in invasive carcinoma, 30 % (3/10) in dysplasia,and 40 % (2/5) in normal biliary epithelium. Bcl-2 and Bax activities were more intense in carcinoma than in dysplasia,with no significant difference in Bcl-2 expression (P=0.1:10),and significant difference in Bax expression (P=0.038). Level of Bax expression was higher in invasive carcinoma than in dysplasia and normal tissue (P=0.012). Bcl-2 expression was correlated to Bax expression (P=0.0059). However, Bcl-2/Bax expression had no correlation with histological subtype,grade of differentiation, or level of invasion.CONCLUSION: Increased Bcl-2/Bax expression from dysplasia to invasive tumors supports the view that this is the usual route for the development of extrahepatic biliary tract carcinoma. Bcl-2/Bax may be involved, at least in part,in the apoptotic activity in extrahepatic biliary carcinoma.

  14. Clinicophatological features of non-hodgkin's lymphoma in children and the relationship of LMP-1 and P53、bcl-2 protein expression%儿童非霍奇金淋巴瘤EB病毒LMP-1和P53、bcl-2表达的关系

    Institute of Scientific and Technical Information of China (English)

    黄波; 郭瑞珍; 明晓务; 王俊; 李青; 唐文台; 肖庆帮

    2003-01-01

    目的探讨儿童NHL EB病毒LMP-1和P53、bcl-2蛋白的表达及关系.方法采用免疫组化Envision法检测64例儿童NHL中LMP-1和P53、bcl-2蛋白.结果 (1)P53蛋白阳性表达39例(60.9%),表达强度与淋巴瘤恶性程度呈正相关;阳性表达率在低恶组与中、高恶性组间有显著性意义,P<0.01.bcl-2蛋白阳性表达37例(53.8%),bcl高于TCL,低恶性高于高恶性.(2)LMP-1蛋白阳性表达45例(70.3%),阳性表达率与肿瘤恶性程度和年龄有统计学意义,P<0.01;而与淋巴瘤免疫表型、性别和发病部位无关.LMP-1表达与P53及bcl-2的表达呈正相关.结论 EBV感染是儿童NHL发生发展不可忽视的病毒致病因素,其致病作用可能是通过上调P53、bcl-2蛋白实现的.

  15. Research Progress of Galectin-3,Bcl-2 and Embryo Development Termination%Galectin-3和Bcl-2与胚胎停育研究进展

    Institute of Scientific and Technical Information of China (English)

    徐耀辉

    2012-01-01

    Galectin-3 is a member of galectin family,which interacts with intracellular glycoprotein,cell surface molecules and extracellular matrix proteins by its carbohydrate recognition domains, participates the progress of embryo implantation,embryogenesis and placenta formation,and establishes and maintains a close relationship with pregnancy. Inhibitors of apoptosis protein Bcl-2 and Galectin-3 have significant sequence similarity,and may have the same apoptosis pathway,which participates in the growth and differentiation of villous trophoblast cells in people's earlier pregnancy and the process of decidualization of endometrium,in addition,playing a critical role in the villous production,growth,placenta formation and in its tissue structure rebuilding and functional perfection.%Galectin-3 是半乳糖凝集素家族中的一员,能通过其糖识别域与细胞内糖蛋白、细胞表面分子和细胞外基质蛋白相互作用,参与胚胎着床、胚胎发生和胎盘形成等过程,与妊娠成功建立和维持密切相关.凋亡抑制蛋白Bcl-2与Galectin-3有明显的序列相似性,可能存在共同细胞凋亡通路,在人早孕过程中参与了绒毛滋养层细胞的增殖和分化、子宫内膜蜕膜化的过程,在绒毛的发生、发育、胎盘形成和组织结构改建及功能完善等方面发挥着重要作用.

  16. Minocycline mechanism of neuroprotection involves the Bcl-2 gene family in optic nerve transection.

    Science.gov (United States)

    Levkovitch-Verbin, Hani; Waserzoog, Yael; Vander, Shelly; Makarovsky, Daria; Ilia, Piven

    2014-10-01

    The second-generation tetracycline, minocycline, has been shown to exhibit neuroprotective therapeutic benefits in many neurodegenerative diseases including experimental glaucoma and optic nerve transection (ONT). This study investigated the mechanism underlying minocycline neuroprotection in a model of ONT. ONT was applied unilaterally in 36 Wistar rat eyes. The rats were randomly divided into a minocycline (22 mg/kg/d) treatment group and a saline treatment group (control). Treatment (minocycline or saline) was given by intraperitoneal injections initiated 3 d before ONT and continued daily until the end of the experiment. The involvement of pro-apoptotic, pro-survival and inflammatory pathways was analyzed by quantitative Real-Time Polymerase Chain Reaction at 4 h and 3 d after the transection in both treatment groups. The involvement of Bcl-2 protein was evaluated by immunohistochemistry. We found that Minocycline significantly increased the expression of the antiapoptotic gene bcl-2 4 h after transection (n = 8, p = 0.008) and decreased the expression of Bax at the same time point (n = 8, p = 0.03). Tumor Necrosis Factor α (TNFα), Inhibitor of Apoptosis Protein (IAP1) and Gadd45α were significantly upregulated in the retinas of eyes with ONTs compared to control (n = 10 for each gene, p = 0.02, p = 0.03, p = 0.04, respectively) but this effect was unaffected by minocycline. This study further support that the mechanism underlying minocycline neuroprotection involves the Bcl-2 gene family, suggesting that minocycline has antiapoptotic properties that support its value as a promising neuroprotective drug. PMID:24410139

  17. Effects of Caspase proteins and Bcl-2 protein of osteoblasts on pathogenesis of postmenopausal osteoporosis%成骨细胞中 Caspase 蛋白和 Bcl-2蛋白在绝经后骨质疏松症发病机理中的作用

    Institute of Scientific and Technical Information of China (English)

    刘嘉眉; 李颖

    2015-01-01

    Objective To investigate the effects of Caspase-3, Caspase-9, B-cell lymphoma-2 ( Bcl-2) protein in the pathogenesis of postmenopausal osteoporosis.Methods From January 2012 to December 2012, 20 cases of hip replacement surgery in the First Affiliated Hospital of Guangzhou Medical University were enrolled.All the patients who were female and in menopause period were divided into the osteoporosis group ( n=10) and the control group ( n=10) .The cancellous bones in the femoral head and femoral neck were collected during the hip replacement and were used to culture osteoblasts.Caspase-3, Caspase-9 and Bcl-2 were examined using enzyme-linked immunosorbent assay ( ELISA) .Two independent samples were compared using t test, if variance unequal, the samples were compared by rank-sum test. Results Compared with the control group, the expression levels of Caspase-3 and Caspase-9 increased and the expression level of Bcl-2 obviously decreased in the osteoporosis group [Caspase-3 (11.0 ±1.5) pmol/L, Caspase-9 (10.9 ±1.7) pmol/L, Bcl-2(1.3 ±0.5) ng/ml];the differences between the two groups were statistically significant ( Caspase-3:t=5.76, P<0.05;Caspase-9:t=4.47, P<0.05; Bcl-2: t=2.43, P<0.05).Conclusion In the process of osteoblast apoptosis in osteoporosis, Caspases-dependent apoptotic pathways may be activated, and the Bcl-2 way is restrained, which may be involved in the pathogenesis of the postmenopausal osteoporosis.%目的:探讨半胱氨酸天冬氨酸蛋白酶(Caspase)-3、Caspase-9、B细胞淋巴瘤-2(Bcl-2)蛋白对绝经后骨质疏松症发病机理的影响。方法2012年1月至2012年12月期间收集广州医科大学附属第一医院老年病科住院的需行髋关节置换手术的女性绝经期患者20例,分为骨质疏松症组与对照组,每组各10例。术中取下股骨头或股骨颈中松质骨,分别进行成骨细胞的体外培养,通过酶联免疫吸附试验( ELISA)方法检测

  18. 尼莫地平对帕金森病模型鼠黑质多巴胺能神经元中Bcl-2、P53蛋白表达的影响%Effect of Nimodipine on the expression of Bcl-2 and P53 protein in dopaminergic neurons of rats with Parkinson's disease

    Institute of Scientific and Technical Information of China (English)

    费娜; 许丽珍

    2007-01-01

    目的 观察尼莫地平对帕金森病模型鼠多巴胺能神经元中Bcl-2、P53蛋白表达的影响,从而探索尼莫地平对黑质多巴胺能神经元的保护作用.方法 建立大鼠PD模型,分组、分阶段用尼莫地平进行干预,第一阶段为尼莫地平对PD模型的预先干预,第二阶段为成功PD模型的药物治疗(尼莫地平、左旋多巴),其后均由阿朴吗啡(Apomorphine)诱导旋转行为,最后予大鼠黑质细胞进行HE、TH、Bcl-2、P53染色.结果 第一阶段:尼莫地平PD模型组(Ⅰ组)和PD模型组(Ⅱ组),成功模型右侧黑质Bcl-2蛋白表达阳性细胞百分比较假手术组(Ⅲ组)和正常对照组(Ⅳ组)低(P<0.05),而P53蛋白表达阳性细胞百分比较Ⅲ组和Ⅳ组高(P<0.05);Ⅰ组右侧黑质Bcl-2蛋白表达阳性细胞百分比高于Ⅱ组(P<0.05),而P53蛋白表达阳性细胞百分比低于Ⅱ组(P<0.05);第二阶段:尼莫地平组、左旋多巴组或二者联用干预组与生理盐水组间右侧黑质Bcl-2、P53蛋白表达阳性细胞百分比无统计学差异(P>0.05).结论 尼莫地平在蛋白合成水平促进了Bcl-2表达、抑制了P53表达,减缓了多巴胺能神经元的凋亡.

  19. 利妥昔单抗注射液联合CHOP方案治疗弥漫大B细胞淋巴瘤及对bcl-2阳性患者的疗效分析%Efficacy analysis on rituximab combined with CHOP scheme in the treatment of diffuse large B-cell lymphoma and positive expression of bcl-2 protein

    Institute of Scientific and Technical Information of China (English)

    韩艳秋; 任燕珍

    2014-01-01

    目的 探讨利妥昔单抗注射液联合CHOP (R-CHOP)治疗弥漫大B细胞淋巴瘤(DLBCL)及对bcl-2阳性表达患者疗效的影响. 方法 回顾性分析内蒙古医科大学附属医院2009年1月至2013年6月确诊为DLBCL的患者108例,根据化疗方案将其分成CHOP组(45例)和R-CHOP组(63例).对两组患者治疗反应进行比较,采用Log-rank检验法对相关的因素进行单因素分析,采用COX回归模型进行多因素分析,并绘制Kaplan-Meier生存曲线.结果 R-CHOP组的完全缓解情况明显优于CHOP组(x2=7.013,P=0.010),且Kaplan-Meier生存曲线显示R-CHOP组的总生存期较CHOP组明显延长(x2=5.066,P=0.024).单因素及多因素分析显示化疗方案的选择、年龄是否> 60岁、乳酸脱氢酶水平是否达正常值及是否完全缓解是DLBCL的不良预后因素(P均<0.05).DLBCL患者bcl-2阳性表达占56.5%(61/108),其中CHOP组bcl-2阳性表达患者的完全缓解情况明显低于bcl-2阴性表达患者(x2=6.000,P=0.031),且bcl-2阳性表达患者中经R-CHOP治疗后其生存期明显优于CHOP组(x2=4.441,P=0.035). 结论 利妥昔单抗注射液可明显提高DLBCL患者的总生存期,且能够改善bcl-2阳性表达患者的疗效.

  20. The functional basis of c-myc and bcl-2 complementation during multistep lymphomagenesis in vivo.

    Science.gov (United States)

    Marin, M C; Hsu, B; Stephens, L C; Brisbay, S; McDonnell, T J

    1995-04-01

    Oncogenes are known to be deregulated by chromosomal translocations occurring at high frequency in specific malignancies. Among the most well characterized of these are c-myc, associated with the t(8;14) in Burkitt's lymphomas, and bcl-2, associated with the t(14;18) in follicular lymphomas. In addition to their role in regulating rates of proliferation, it is known that oncogenes and tumor suppressor genes can also regulate rates of apoptotic cell death. The contribution of c-myc and bcl-2 to the regulation of cell death during lymphomagenesis in vivo is assessed using bcl-2-Ig and emu-myc trangenic mice and bcl-2/myc hybrid transgenic mice. Translocations between the endogenous c-myc gene and immunoglobulin loci, e.g., t(12;15), are common in lymphomas arising in the bcl-2-Ig mice. Furthermore, bcl-2/c-myc double transgenic mice exhibit accelerated lymphomagenesis, indicating cooperation between these two oncogenes. Genetic complementation of c-myc and bcl-2 during lymphomagenesis resulted from the suppression of c-myc-associated apoptosis. Other genes are likely involved in regulating cell death during multistep lymphomagenesis. PMID:7698223

  1. Curcumin induces the expression of NF-κB and Bcl-2/Bax in human renal cell carcinoma cell line ACHN

    Institute of Scientific and Technical Information of China (English)

    Gang Li; Tie Chong; Ziming Wang

    2009-01-01

    Objective: To explore the in vitro effects of curcumin on the proliferation and apoptosis of the human renal cell carcinoma cell line ACHN, and to investigate its mechanisms of action. Methods: The human renal cell carcinoma cell line ACHN was treated with different concentrations of curcumin for 24 h. The MTT assay was used to evaluate the cytotoxic effects of curcumin and flow cytometry was utilized to observe and detect the apoptosis of ACHN cells induced by curcumin. The expression levels of Bcl-2, Bax and NF-κBP65 mRNA were evaluated by Reverse Transcription-Polymerase Chain Reaction (RT-PCR), while the expression of Bcl-2, Bax, NF-κBP65 and IkB proteins was evaluated by Western blot. Results: The concentrations of curcumin used significantly inhibited the proliferation of ACHN human renal cell carcinoma cells in vitro in a dose and time-dependent manner (Ftime=5.55, P < 0.05; Fdose=110.05, P < 0.05). Obvious apoptosis of cells treated with different concentrations of curcumin could be observed by FCM. Compared with the control group, the apoptosis rates of curcumin-treated cells were markedly increased (F=96.35, P < 0.05). Lower dose of curcumin significantly induced the apoptosis of ACHN cells. With intervention of different concentrations of curcumin (0, 10, 20 and 40 μmol/L) for 24 h, the expression levels of Bcl-2 and NF-κBP65 mRNA in ACHN cells were decreased while the expression level of Bax mRNA was increased (P < 0.05), and Bcl-2, and NF-κBP65 protein decreased, while Bax and IκB protein increased compared with those in the untreated group. Conclusion: Curcumin inhibited proliferation and increased apoptosis of the human renal cell carcinoma cell line ACHN. These curcumin effects appear to involve up-regulating IκB, down-regulating NF-κB, and regulating the expression of the apoptosis genes Bcl-2/Bax.

  2. Sulphoraphane, a naturally occurring isothiocyanate induces apoptosis in breast cancer cells by targeting heat shock proteins

    Energy Technology Data Exchange (ETDEWEB)

    Sarkar, Ruma; Mukherjee, Sutapa [Department of Environmental Carcinogenesis and Toxicology, Chittaranjan National Cancer Institute, 37, SP Mukherjee Road, Kolkata 700 026 (India); Biswas, Jaydip [Chittaranjan National Cancer Institute, 37, SP Mukherjee Road, Kolkata 700 026 (India); Roy, Madhumita, E-mail: mitacnci@yahoo.co.in [Department of Environmental Carcinogenesis and Toxicology, Chittaranjan National Cancer Institute, 37, SP Mukherjee Road, Kolkata 700 026 (India)

    2012-10-12

    Highlights: Black-Right-Pointing-Pointer HSPs (27, 70 and 90) and HSF1 are overexpressed in MCF-7 and MDA-MB-231 cells. Black-Right-Pointing-Pointer Sulphoraphane, a natural isothiocyanate inhibited HSPs and HSF1 expressions. Black-Right-Pointing-Pointer Inhibition of HSPs and HSF1 lead to regulation of apoptotic proteins. Black-Right-Pointing-Pointer Alteration of apoptotic proteins activate of caspases particularly caspase 3 and 9 leading to induction of apoptosis. Black-Right-Pointing-Pointer Alteration of apoptotic proteins induce caspases leading to induction of apoptosis. -- Abstract: Heat shock proteins (HSPs) are involved in protein folding, aggregation, transport and/or stabilization by acting as a molecular chaperone, leading to inhibition of apoptosis by both caspase dependent and/or independent pathways. HSPs are overexpressed in a wide range of human cancers and are implicated in tumor cell proliferation, differentiation, invasion and metastasis. HSPs particularly 27, 70, 90 and the transcription factor heat shock factor1 (HSF1) play key roles in the etiology of breast cancer and can be considered as potential therapeutic target. The present study was designed to investigate the role of sulphoraphane, a natural isothiocyanate on HSPs (27, 70, 90) and HSF1 in two different breast cancer cell lines MCF-7 and MDA-MB-231 cells expressing wild type and mutated p53 respectively, vis-a-vis in normal breast epithelial cell line MCF-12F. It was furthermore investigated whether modulation of HSPs and HSF1 could induce apoptosis in these cells by altering the expressions of p53, p21 and some apoptotic proteins like Bcl-2, Bax, Bid, Bad, Apaf-1 and AIF. Sulphoraphane was found to down-regulate the expressions of HSP70, 90 and HSF1, though the effect on HSP27 was not pronounced. Consequences of HSP inhibition was upregulation of p21 irrespective of p53 status. Bax, Bad, Apaf-1, AIF were upregulated followed by down-regulation of Bcl-2 and this effect was prominent

  3. Sulphoraphane, a naturally occurring isothiocyanate induces apoptosis in breast cancer cells by targeting heat shock proteins

    International Nuclear Information System (INIS)

    Highlights: ► HSPs (27, 70 and 90) and HSF1 are overexpressed in MCF-7 and MDA-MB-231 cells. ► Sulphoraphane, a natural isothiocyanate inhibited HSPs and HSF1 expressions. ► Inhibition of HSPs and HSF1 lead to regulation of apoptotic proteins. ► Alteration of apoptotic proteins activate of caspases particularly caspase 3 and 9 leading to induction of apoptosis. ► Alteration of apoptotic proteins induce caspases leading to induction of apoptosis. -- Abstract: Heat shock proteins (HSPs) are involved in protein folding, aggregation, transport and/or stabilization by acting as a molecular chaperone, leading to inhibition of apoptosis by both caspase dependent and/or independent pathways. HSPs are overexpressed in a wide range of human cancers and are implicated in tumor cell proliferation, differentiation, invasion and metastasis. HSPs particularly 27, 70, 90 and the transcription factor heat shock factor1 (HSF1) play key roles in the etiology of breast cancer and can be considered as potential therapeutic target. The present study was designed to investigate the role of sulphoraphane, a natural isothiocyanate on HSPs (27, 70, 90) and HSF1 in two different breast cancer cell lines MCF-7 and MDA-MB-231 cells expressing wild type and mutated p53 respectively, vis-à-vis in normal breast epithelial cell line MCF-12F. It was furthermore investigated whether modulation of HSPs and HSF1 could induce apoptosis in these cells by altering the expressions of p53, p21 and some apoptotic proteins like Bcl-2, Bax, Bid, Bad, Apaf-1 and AIF. Sulphoraphane was found to down-regulate the expressions of HSP70, 90 and HSF1, though the effect on HSP27 was not pronounced. Consequences of HSP inhibition was upregulation of p21 irrespective of p53 status. Bax, Bad, Apaf-1, AIF were upregulated followed by down-regulation of Bcl-2 and this effect was prominent in MCF-7 than in MDA-MB-231. However, very little change in the expression of Bid was observed. Alteration in Bcl-2 Bax

  4. Expression of Inducible Nitric Oxide Synthase, p53 and Bcl-2 in Gastric Precancerous and Cancerous Lesions: Correlation with Clinical Features

    Institute of Scientific and Technical Information of China (English)

    Tao Cui; Zu'an Zhu; Ying Liu; Qingyan Kong; Sujuan Fei

    2006-01-01

    OBJECTIVE To explore the expression of inducible nitric oxide synthase(iNOS), p53 and bcl-2 in gastric precancerous and cancerous lesions and to examine the expression of these proteins in relation to clinical features.METHODS The expressions of iNOS, p53 and bcl-2 proteins in gastric precancerous and cancerous lesions and their correlations with the clinical features were determined using immunohistochemical assays (Power VisionTM two-step method) on 84 gastric carcinomas and 54 gastric atypical hyperplastic tissues. Apoptotic cells were evaluated by terminal deoxynucleotidyl transferase- mediated dUTP-biotin nick-end labeling (TUNEL).RESULTS Expression of iNOS, p53 and bcl-2 was significantly higher in gastric carcinoma (GC) tissues than in gastric atypical hyperplastic tissues. Among the 84 carcinomas, the expression of p53 was observed in 50 (59.52%), bcl-2 in 43 (51.19%), and iNOS in 65 (77.58%). Overexpression of iNOS and bcl-2 in gastrlc carcinoma was related to tumor size and iNOS was related to the presence of lymph node metastasis (P<0.05). The expression of proteins did not correlate with age, sex, stage of disease, or differentiation. Expression of iNOS in gastric carcinoma tissues was positively correlated with bcl-2 expression (χ2=8.926, P=0.003),and also with p53 expression (χ2= 5.2430, P= 0.022). The mean apoptotic indexes (Al) were 1.29%±0.50 in low-grade atypical hyperplasia (LG),0.96%±0.36 in high-grade atypical hyperplasia (HG) and 0.70%±0.43 in GC, with the difference being significant between LG, HG and GC (P<0.05). There was a significant positive correlation between iNOS expression and the Al in GC (t=3.0815, P=0.0028).CONCLUSION iNOS was expressed in the majority of gastric carcinoma tissues and correlated with cellular apoptosis associated with p53 and bcl-2 expression. iNOS overexpression is closely associated with p53 and bcl-2 accumulation status. iNOS may play a synergistic role in the pathogenesis of GC.

  5. Prognostic significance of CD95, P53, and BCL2 expression in extranodal non-Hodgkin's lymphoma

    OpenAIRE

    Chatzitolios, Anastasios; Venizelos, Ioannis; Tripsiannis, Gregory; Anastassopoulos, George; Papadopoulos, Nikolaos

    2010-01-01

    Abstract Apoptosis-related proteins play an important role in lymphoma cell death during chemotherapy. In our study, we investigated the prognostic significance of CD95, BCL2, and P53 expression in extranodal non-Hodgkin?s lymphoma (NHL). We examined 71 patients with extranodal NHL [45 diffuse large B-cell lymphomas (DLBCLs) and 26 mucosa-associated lymphoid tissue lymphomas (MALTLs)], 35 male and 36 female, with a median age of 65.8 years. The most common site of origin was the st...

  6. Intrinsic and extrinsic pathway signaling during neuronal apoptosis

    OpenAIRE

    Putcha, Girish V.; Harris, Charles A; Moulder, Krista L.; Easton, Rachael M.; Thompson, Craig B.; Johnson, Eugene M.

    2002-01-01

    Trophic factor deprivation (TFD)-induced apoptosis in sympathetic neurons requires macromolecular synthesis–dependent BAX translocation, cytochrome c (cyt c) release, and caspase activation. Here, we report the contributions of other intrinsic and extrinsic pathway signals to these processes. Sympathetic neurons expressed all antiapoptotic BCL-2 proteins examined, yet expressed only certain BH3-only and multidomain proapoptotic BCL-2 family members. All coexpressed proapoptotic proteins did n...

  7. A PRELIMINARY STUDY ON SURVIVIN AND BCL-2 EXPRESSION IN CERVICAL CARCINOMAS

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective To study the expression of a novel inhibitor of apptosis and survivin in cervical carcinoma and its relationship to the expression of Bcl-2.Methods Using SP immunohistochemical technique, we examined the expression of survivin and Bcl-2 in 59 cervical invasive squamous cell carcinomas.Results Survivin was expressed in 41 of 59 cases(69.5%) of cervical carcinomas. In contrast, no expression of survivin in normal cervical tissues was observed. Overexpression of survivin was related to the tumor grade and clinical stage. Survivin positive cases were strongly associated with Bcl-2 expression(80% versus 35.7%;P<0.005).Conclusion Apoptosis inhibition by survivin abnormal expression, alone or in cooperation with Bcl-2, may participate in the onset and progression of cervical carcinoma. Survivin is a new diagnostic/therapeutic target in cervical cancer.

  8. Of humans and canines: Immunohistochemical analysis of PCNA, Bcl-2, p53, cytokeratin and ER in mammary tumours.

    Science.gov (United States)

    Kumaraguruparan, R; Prathiba, D; Nagini, S

    2006-10-01

    Mammary tumours are the most common neoplasms in humans and canines. Human and canine mammary tumours share several important epidemiological, clinicopathological and biochemical features. Development of mammary tumours involves accumulation of mutant cells caused by excessive proliferation and insufficient apoptosis or dysregulation of cellular differentiation. The present study was therefore designed to investigate the expression of proliferation, differentiation, and apoptosis associated proteins together with expression of estrogen receptors (ER) in both human and canine mammary tumours. Thirty breast cancer patients categorized as pre- and postmenopausal, and 30 mammary gland tumours obtained from bitches were included in this study. The expression of proliferating cell nuclear antigen (PCNA), Bcl-2, p53, cytokeratin and ER in tumour tissues and adjacent tissues were investigated using immunohistochemical staining. While the expression of PCNA, Bcl-2, p53 and ER was significantly increased, expression of cytokeratin was significantly lower in both human as well as canine mammary tumours compared to corresponding adjacent tissues. The magnitude of the changes was however more pronounced in premenopausal patients compared to postmenopausal patients. The changes in proliferation, apoptosis and differentiation associated proteins in human and canine mammary tumours validate use of the canine model to understand the molecular mechanisms of mammary carcinogenesis. PMID:16740286

  9. Ekspresi Bcl-2 dan Caspase-3 Pascapaparan Hipoksia Hipobarik Intermiten

    OpenAIRE

    Achmad Hidayat; Kahdar Wiradisastra; Bethy S. Hernowo; Tri Hanggono Achmad

    2011-01-01

    Intermittent hypobaric hypoxia often suffered by cabin crew due to the fact that they are breathing lower pressured air inside the plane cabin. Human body will adapt by binding more oxygen and reducing hypoxia effect. Mitochondria function will be irritated by hypoxia which affect, outer mithochondrial membrane permeability due to decrease of Bcl-2 protein. Later on if hypoxia continues mitochondrial membrane will leaked cytocrome-c will released and apoptotic pathway will occur. The purpose ...

  10. Clinical significance of bax/bcl-2 ratio in chronic lymphocytic leukemia

    Science.gov (United States)

    Del Principe, Maria Ilaria; Bo, Michele Dal; Bittolo, Tamara; Buccisano, Francesco; Rossi, Francesca Maria; Zucchetto, Antonella; Rossi, Davide; Bomben, Riccardo; Maurillo, Luca; Cefalo, Mariagiovanna; De Santis, Giovanna; Venditti, Adriano; Gaidano, Gianluca; Amadori, Sergio; de Fabritiis, Paolo; Gattei, Valter; Del Poeta, Giovanni

    2016-01-01

    In chronic lymphocytic leukemia the balance between the pro-apoptotic and anti-apoptotic members of the bcl-2 family is involved in the pathogenesis, chemorefractoriness and clinical outcome. Moreover, the recently proposed anti-bcl-2 molecules, such as ABT-199, have emphasized the potential role of of bcl-2 family proteins in the context of target therapies. We investigated bax/bcl-2 ratio by flow cytometry in 502 patients and identified a cut off of 1.50 to correlate bax/bcl-2 ratio with well-established clinical and biological prognosticators. Bax/bcl-2 was 1.50 or over in 263 patients (52%) with chronic lymphocytic leukemia. Higher bax/bcl-2 was associated with low Rai stage, lymphocyte doubling time over 12 months, beta-2 microglobulin less than 2.2 mg/dL, soluble CD23 less than 70 U/mL and a low risk cytogenetic profile (P<0.0001). On the other hand, lower bax/bcl-2 was correlated with unmutated IGHV (P<0.0001), mutated NOTCH1 (P<0.0001) and mutated TP53 (P=0.00007). Significant shorter progression-free survival and overall survival were observed in patients with lower bax/bcl-2 (P<0.0001). Moreover, within IGHV unmutated (168 patients) and TP53 mutated (37 patients) subgroups, higher bax/bcl-2 identified cases with significant longer PFS (P=0.00002 and P=0.039). In multivariate analysis of progression-free survival and overall survival, bax/bcl-2 was an independent prognostic factor (P=0.0002 and P=0.002). In conclusion, we defined the prognostic power of bax/bcl-2 ratio, as determined by a flow cytometric approach, and highlighted a correlation with chemoresistance and outcome in chronic lymphocytic leukemia. Finally, the recently proposed new therapies employing bcl-2 inhibitors prompted the potential use of bax/bcl-2 ratio to identify patients putatively resistant to these molecules. PMID:26565002

  11. Targeting BCL-2 and ABL/LYN in Philadelphia chromosome-positive acute lymphoblastic leukemia.

    Science.gov (United States)

    Leonard, Jessica T; Rowley, Joelle S J; Eide, Christopher A; Traer, Elie; Hayes-Lattin, Brandon; Loriaux, Marc; Spurgeon, Stephen E; Druker, Brian J; Tyner, Jeffrey W; Chang, Bill H

    2016-08-31

    Treatment of Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph(+)ALL) remains a challenge. Although the addition of targeted tyrosine kinase inhibitors (TKIs) to standard cytotoxic therapy has greatly improved upfront treatment, treatment-related morbidity and mortality remain high. TKI monotherapy provides only temporary responses and renders patients susceptible to the development of TKI resistance. Thus, identifying agents that could enhance the activity of TKIs is urgently needed. Recently, a selective inhibitor of B cell lymphoma 2 (BCL-2), ABT-199 (venetoclax), has shown impressive activity against hematologic malignancies. We demonstrate that the combination of TKIs with venetoclax is highly synergistic in vitro, decreasing cell viability and inducing apoptosis in Ph(+)ALL. Furthermore, the multikinase inhibitors dasatinib and ponatinib appear to have the added advantage of inducing Lck/Yes novel tyrosine kinase (LYN)-mediated proapoptotic BCL-2-like protein 11 (BIM) expression and inhibiting up-regulation of antiapoptotic myeloid cell leukemia 1 (MCL-1), thereby potentially overcoming the development of venetoclax resistance. Evaluation of the dasatinib-venetoclax combination for the treatment of primary Ph(+)ALL patient samples in xenografted immunodeficient mice confirmed the tolerability of this drug combination and demonstrated its superior antileukemic efficacy compared to either agent alone. These data suggest that the combination of dasatinib and venetoclax has the potential to improve the treatment of Ph(+)ALL and should be further evaluated for patient care. PMID:27582059

  12. Carboxypeptidase E Protects Hippocampal Neurons During Stress in Male Mice by Up-regulating Pro-survival BCL2 Protein Expression

    OpenAIRE

    Murthy, S. R. K.; Thouennon, E.; Li, W.-S.; Cheng, Y; Bhupatkar, J.; Cawley, N.X.; Lane, M.; Merchenthaler, I; Loh, Y P

    2013-01-01

    Prolonged chronic stress causing elevated plasma glucocorticoids leads to neurodegeneration. Adaptation to stress (allostasis) through neuroprotective mechanisms can delay this process. Studies on hippocampal neurons have identified carboxypeptidase E (CPE) as a novel neuroprotective protein that acts extracellularly, independent of its enzymatic activity, although the mechanism of action is unclear. Here, we aim to determine if CPE plays a neuroprotective role in allostasis in mouse hippocam...

  13. Dendrosomal curcumin nanoformulation modulate apoptosis-related genes and protein expression in hepatocarcinoma cell lines.

    Science.gov (United States)

    Montazeri, Maryam; Sadeghizadeh, Majid; Pilehvar-Soltanahmadi, Yones; Zarghami, Faraz; Khodi, Samaneh; Mohaghegh, Mina; Sadeghzadeh, Hadi; Zarghami, Nosratollah

    2016-07-25

    The side-effects observed in conventional therapies have made them unpromising in curing Hepatocellular carcinoma; therefore, developing novel treatments can be an overwhelming significance. One of such novel agents is curcumin which can induce apoptosis in various cancerous cells, however, its poor solubility is restricted its application. To overcome this issue, this paper employed dendrosomal curcumin (DNC) was employed to in prevent hepatocarcinoma in both RNA and protein levels. Hepatocarcinoma cells, p53 wild-type HepG2 and p53 mutant Huh7, were treated with DNC and investigated for toxicity study using MTT assay. Cell cycle distribution and apoptosis were analyzed using Flow-cytometry and Annexin-V-FLUOS/PI staining. Real-time PCR and Western blot were employed to analyze p53, BAX, Bcl-2, p21 and Noxa in DNC-treated cells. DNC inhibited the growth in the form of time-dependent manner, while the carrier alone was not toxic to the cell. Flow-cytometry data showed the constant concentration of 20μM DNC during the time significantly increases cell population in SubG1 phase. Annexin-V-PI test showed curcumin-induced apoptosis was enhanced in Huh7 as well as HepG2, compared to untreated cells. Followed by treatment, mRNA expression of p21, BAX, and Noxa increased, while the expression of Bcl-2 decreased, and unlike HepG2, Huh7 showed down-regulation of p53. In summary, DNC-treated hepatocellular carcinoma cells undergo apoptosis by changing the expression of genes involved in the apoptosis and proliferation processes. These findings suggest that DNC, as a plant-originated therapeutic agent, could be applied in cancer treatment. PMID:27234697

  14. Silencing Bcl-2 Expression in Epithelial Cancer Cells Using “Smart” Particles

    OpenAIRE

    Yen-Ling Lin; Guohua Jiang; Zhaocheng Zhang; Jacques E Nör; Mohamed E H ElSayed

    2014-01-01

    Short interfering RNA (siRNA) targeted against anti-apoptotic Bcl-2 protein proved to knockdown its expression and trigger cancer cell death. We used degradable, pH-sensitive, comb-like [P(EAA-co-BMA)-b-PNASI-g-P(HMA-co-TMAEMA)] polymer to condense anti-Bcl-2 siRNA into “smart” particles, which proved to shuttle their cargo past the endosomal membrane and into the cytoplasm of HeLa and UM-SCC-17B cancer cells. HeLa and UM-SCC-17B cancer cells were treated with anti-Bcl-2 particles followed by...

  15. Antisense bcl-2 treatment increases programmed cell death in non-small cell lung cancer cell lines.

    Science.gov (United States)

    Koty, P P; Zhang, H; Levitt, M L

    1999-02-01

    Programmed cell death (PCD) is a genetically regulated pathway that is altered in many cancers. This process is, in part, regulated by the ratio of PCD inducers (Bax) or inhibitors (Bcl-2). An abnormally high ratio of Bcl-2 to Bax prevents PCD, thus contributing to resistance to chemotherapeutic agents, many of which are capable of inducing PCD. Non-small cell lung cancer (NSCLC) cells demonstrate resistance to these PCD-inducing agents. If Bcl-2 prevents NSCLC cells from entering the PCD pathway, then reducing the amount of endogenous Bcl-2 product may allow these cells to spontaneously enter the PCD pathway. Our purpose was to determine the effects of bcl-2 antisense treatment on the levels of programmed cell death in NSCLC cells. First, we determined whether bcl-2 and bax mRNA were expressed in three morphologically distinct NSCLC cell lines: NCI-H226 (squamous), NCI-H358 (adenocarcinoma), and NCI-H596 (adenosquamous). Cells were then exposed to synthetic antisense bcl-2 oligonucleotide treatment, after which programmed cell death was determined, as evidenced by DNA fragmentation. Bcl-2 protein expression was detected immunohistochemically. All three NSCLC cell lines expressed both bcl-2 and bax mRNA and had functional PCD pathways. Synthetic antisense bcl-2 oligonucleotide treatment resulted in decreased Bcl-2 levels, reduced cell proliferation, decreased cell viability, and increased levels of spontaneous PCD. This represents the first evidence that decreasing Bcl-2 in three morphologically distinct NSCLC cell lines allows the cells to spontaneously enter a PCD pathway. It also indicates the potential therapeutic use of antisense bcl-2 in the treatment of NSCLC. PMID:10217615

  16. α/β-hydrolase domain containing protein 15 (ABHD15--an adipogenic protein protecting from apoptosis.

    Directory of Open Access Journals (Sweden)

    Evelyn Walenta

    Full Text Available Our knowledge about adipocyte metabolism and development is steadily growing, yet many players are still undefined. Here, we show that α/β-hydrolase domain containing protein 15 (Abhd15 is a direct and functional target gene of peroxisome proliferator-activated receptor gamma (PPARγ, the master regulator of adipogenesis. In line, Abhd15 is mainly expressed in brown and white adipose tissue and strongly upregulated during adipogenesis in various murine and human cell lines. Stable knockdown of Abhd15 in 3T3-L1 cells evokes a striking differentiation defect, as evidenced by low lipid accumulation and decreased expression of adipocyte marker genes. In preconfluent cells, knockdown of Abhd15 leads to impaired proliferation, which is caused by apoptosis, as we see an increased SubG1 peak, caspase 3/7 activity, and BAX protein expression as well as a reduction in anti-apoptotic BCL-2 protein. Furthermore, apoptosis-inducing amounts of palmitic acid evoke a massive increase of Abhd15 expression, proposing an apoptosis-protecting role for ABHD15. On the other hand, in mature adipocytes physiological (i.e. non-apoptotic concentrations of palmitic acid down-regulate Abhd15 expression. Accordingly, we found that the expression of Abhd15 in adipose tissue is reduced in physiological situations with high free fatty acid levels, like high-fat diet, fasting, and aging as well as in genetically obese mice. Collectively, our results position ABHD15 as an essential component in the development of adipocytes as well as in apoptosis, thereby connecting two substantial factors in the regulation of adipocyte number and size. Together with its intricate regulation by free fatty acids, ABHD15 might be an intriguing new target in obesity and diabetes research.

  17. Expression of bax、bcl-2、CD44v6、nm23 protein in transitional cell carcinoma of the bladder%膀胱移行细胞癌中bax、bcl-2、CD44v6、nm23表达

    Institute of Scientific and Technical Information of China (English)

    张玉华; 陈萍; 朴颖实; 韩影; 李弘; 张伟东; 刘宪军; 巩雷; 谢江

    2004-01-01

    目的探讨bax、bcl-2、CD44、nm23基因蛋白在膀胱移行细胞癌(TCC)中的表达.方法应用免疫组化S-P法对64例膀胱TCC及20例正常膀胱黏膜组织中bax、bcl-2、CD44v6、nm23进行检测.结果 64例膀胱TCC中bax阳性率为17.2%(11/64),正常膀胱黏膜组织为90.0%(18/20)(P《0.05). 膀胱TCC中bcl-2阳性表达率为82.8%(53/64),正常膀胱黏膜为20.0%(4/20)(P《0.05).bax 、bcl-2阳性率随组织学分级的提高有逐渐增强的趋势,但无统计学意义(P》0.05);在无浸润及有深层浸润的膀胱TCC中,bax的阳性表达率分别为16.3%、20.0%(P》0.05),bcl-2则分别为83.7%、80.0%(P》0.05);在无复发转移及有复发转移的膀胱TCC中,bax阳性率分别为16.1%、25.0%(P》0.05),bcl-2分别为82.1%、87.5%(P》0.05).64例膀胱TCC中CD44v6阳性表达率为50.0%(32/64),正常膀胱黏膜组织为5.0%(1/20)(P《0.05).nm23在膀胱TCC中的阳性率为76.6%(49/64),正常膀胱黏膜组织为20.0%(4/20)(P《0.05).CD44v6阳性率Ⅰ、Ⅱ级与Ⅲ级相比差异有显著性(P《0.05),nm23阳性率Ⅰ级与Ⅱ、Ⅲ级相比差异有显著性(P《0.05);在有深层浸润的膀胱TCC中CD44v6、nm 23阳性表达率均明显高于无浸润的病例(P《0.05);有复发转移的膀胱TCC CD44v6阳性率高于无复发转移的病例(P《0.05),而nm23在膀胱TCC中的阳性表达率与有无复发转移无明显相关性(P》0.05).结论 bax表达水平下降及bcl-2的表达增强在膀胱TCC的发生中起到重要作用,CD44v6、nm23也参与促进了膀胱TCC的发生.bax、bcl-2与肿瘤的组织学分级、浸润深度、复发、转移等无关,但CD44v6与之呈正相关.nm23与组织学分级、浸润深度呈正相关,而与复发或转移无相关性.

  18. 甘草黄酮对大强度耐力运动大鼠肾脏组织Ca2+、Mg2+-ATPase及Bax,Bc1-2蛋白表达的影响%Effect of High-Intensity Endurance Exercise on Ca2+,Mg2+-ATPase and Bax, Bcl-2 Protein Expression With Glycyrrhiza Flavonoids in rat Nephridial Tissue

    Institute of Scientific and Technical Information of China (English)

    王东旭; 陈艳艳

    2013-01-01

    Objective To explore Glycyrrhiza Elavonoids on the rat nephridial tissue of Ca2+, Mg2+-ATPase and Bax, Bcl-2 protein expression with high-intensity endurance exercise. Methods The twenty-four healthy male rats were randomly divided into quiet groups, high-intensity exercise group and exercise plus Glycyrrhiza Elavonoids group, After 6 weeks of treadmill training, Using the box of reagent and immunity histochemistry examined the changing of Ca2+, Mg2+-ATPase and Bax, Bcl-2 protein expression on each groups . Results Compared with the quiet groups, the activity of Ca2+, Mg2+-ATPase both had significant droped (P<0.01), and the groups of plus drog had very difference increased than high-intendity exerxise groups (P<0.01); High-intensity endurance exercise group and exercise dosing rats AI apoptosis index increased in varying degrees;high-intensity exercise group (MOD) were very significant difference(P<0.01), exercise plus drug group Bac protein expression (MOD)were very significant difference (P<0.01); Exercise plus drug group Bcl-2 protein expression(MOD) with the high-intersity exercise group had significant difference(P<0.01), High-intensity exercise group and exercise plus drug group Bax/Bcl-2 ratio of distribution is significantly difference degrees of difference(P<0.05,P<0.01).%目的:探讨甘草黄酮对大强度耐力运动大鼠肾脏组织Ca2+、Mg2+-ATPase及Bax、Bcl-2表达的影响。方法:选取SD雄性健康大鼠24只,随机分为安静组、大强度运动组和运动加药组;采用跑台训练6周后取材,应用试剂盒和免疫组织化学法测检测各组大鼠肾脏组织Ca2+、Mg2+-TPase活性及Bax和Bcl-2表达的变化。结果:与安静对照组相比,大强度运动组和运动加药组肾脏组织Ca2+、Mg2+-TPase活性均呈非常显著性下降(P<0.01);其中运动加药组Ca2+、Mg2+-TPase活性均较大强度运动组具有非常显著差异性提高(P<0.01);大强度耐力运动组和运动加

  19. Involvement of PI3K and MAPK Signaling in bcl-2-induced Vascular Endothelial Growth Factor Expression in Melanoma Cells

    Science.gov (United States)

    Trisciuoglio, Daniela; Iervolino, Angela; Zupi, Gabriella; Del Bufalo, Donatella

    2005-01-01

    We have previously demonstrated that bcl-2 overexpression in tumor cells exposed to hypoxia increases the expression of vascular endothelial growth factor (VEGF) gene through the hypoxia-inducible factor-1 (HIF-1). In this article, we demonstrate that exposure of bcl-2 overexpressing melanoma cells to hypoxia induced phosphorylation of AKT and extracellular signal-regulated kinase (ERK)1/2 proteins. On the contrary, no modulation of these pathways by bcl-2 was observed under normoxic conditions. When HIF-1α expression was reduced by RNA interference, AKT and ERK1/2 phosphorylation were still induced by bcl-2. Pharmacological inhibition of mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3-kinase (PI3K) signaling pathways reduced the induction of VEGF and HIF-1 in response to bcl-2 overexpression in hypoxia. No differences were observed between control and bcl-2-overexpressing cells in normoxia, in terms of VEGF protein secretion and in response to PI3K and MAPK inhibitors. We also demonstrated that RNA interference-mediated down-regulation of bcl-2 expression resulted in a decrease in the ERK1/2 phosphorylation and VEGF secretion only in bcl-2-overexpressing cell exposed to hypoxia but not in control cells. In conclusion, our results indicate, for the first time, that bcl-2 synergizes with hypoxia to promote expression of angiogenesis factors in melanoma cells through both PI3K- and MAPK-dependent pathways. PMID:15987743

  20. American Ginseng Stimulates Insulin Production and Prevents Apoptosis through Regulation of Uncoupling Protein-2 in Cultured β Cells

    Directory of Open Access Journals (Sweden)

    John Zeqi Luo

    2006-01-01

    Full Text Available American ginseng root displays the ability to achieve glucose homeostasis both experimentally and clinically but the unknown mechanism used by ginseng to achieve its therapeutic effects on diabetes limits its application. Disruption in the insulin secretion of pancreatic β cells is considered the major cause of diabetes. A mitochondrial protein, uncoupling protein-2 (UCP-2 has been found to play a critical role in insulin synthesis and β cell survival. Our preliminary studies found that the extracts of American ginseng inhibit UCP-2 expression which may contribute to the ability of ginseng protecting β cell death and improving insulin synthesis. Therefore, we hypothesized that ginseng extracts suppress UCP-2 in the mitochondria of pancreatic β cells, promoting insulin synthesis and anti-apoptosis (a programmed cell-death mechanism. To test the hypothesis, the serum-deprived quiescent β cells were cultured with or without interleukin-1β (IL-1β, (200 pg ml−1, a cytokine to induce β cell apoptosis and water extracts of American ginseng (25 μg per 5 μl administered to wells of 0.5 ml culture for 24 h. We evaluated effects of ginseng on UCP-2 expression, insulin production, anti-/pro-apoptotic factors Bcl-2/caspase-9 expression and cellular ATP levels. We found that ginseng suppresses UCP-2, down-regulates caspase-9 while increasing ATP and insulin production/secretion and up-regulates Bcl-2, reducing apoptosis. These findings suggest that stimulation of insulin production and prevention of β cell loss by American ginseng extracts can occur via the inhibition of mitochondrial UCP-2, resulting in increase in the ATP level and the anti-apoptotic factor Bcl-2, while down-regulation of pro-apoptotic factor caspase-9 occurs, lowering the occurrence of apoptosis, which support the hypothesis.

  1. Apoptosis and morphological changes in hippocampus of rat brain after hemisphere irradiation

    International Nuclear Information System (INIS)

    Objective: To study the apoptosis, the expression of bcl-2 and the morphological changes of various tissue components in the rat hippocampus after hemisphere irradiation. Methods: The DNA contents and the quantities of bcl-2 protein were analyzed by flow cytometry. The histological sections were examined by electron and light microscopy. Results: The apoptosis of hippocampal cells in the irradiated brain increased in most of the rats, the expression of bcl-2 decreased in the meantime,and those changes were significant only in the groups irradiated within 1 month. Necrosis was observed in some of the 30 Gy-3-month-period group. Different levels of morphological changes in blood vessels, neuro-glia cells and neurons were found in rats of all other groups. Conclusion: After hemisphere irradiation, apoptosis increases, bcl-2 protein decreases, and various components in the hippocampus change. These data suggest a possible association between the damage of various components and development of radiation-induced brain toxicity

  2. The deubiquitinase Usp27x stabilizes the BH3-only protein Bim and enhances apoptosis.

    Science.gov (United States)

    Weber, Arnim; Heinlein, Melanie; Dengjel, Jörn; Alber, Claudia; Singh, Prafull Kumar; Häcker, Georg

    2016-05-01

    Bim is a pro-apoptotic Bcl-2 family member of the BH3-only protein subgroup. Expression levels of Bim determine apoptosis susceptibility in non-malignant and in tumour cells. Bim protein expression is downregulated by proteasomal degradation following ERK-dependent phosphorylation and ubiquitination. Here, we report the identification of a deubiquitinase, Usp27x, that binds Bim upon its ERK-dependent phosphorylation and can upregulate its expression levels. Overexpression of Usp27x reduces ERK-dependent Bim ubiquitination, stabilizes phosphorylated Bim, and induces apoptosis in PMA-stimulated cells, as well as in tumour cells with a constitutively active Raf/ERK pathway. Loss of endogenous Usp27x enhances the Bim-degrading activity of oncogenic Raf. Overexpression of Usp27x induces low levels of apoptosis in melanoma and non-small cell lung cancer (NSCLC) cells and substantially enhances apoptosis induced in these cells by the inhibition of ERK signalling. Finally, deletion of Usp27x reduces apoptosis in NSCLC cells treated with an EGFR inhibitor. Thus, Usp27x can trigger via its proteolytic activity the deubiquitination of Bim and enhance its levels, counteracting the anti-apoptotic effects of ERK activity, and therefore acts as a tumour suppressor. PMID:27013495

  3. Inclusion Complex of Zerumbone with Hydroxypropyl- β -Cyclodextrin Induces Apoptosis in Liver Hepatocellular HepG2 Cells via Caspase 8/BID Cleavage Switch and Modulating Bcl2/Bax Ratio

    OpenAIRE

    Nabilah Muhammad Nadzri; Ahmad Bustamam Abdul; Mohd Aspollah Sukari; Siddig Ibrahim Abdelwahab; Eid, Eltayeb E. M.; Syam Mohan; Behnam Kamalidehghan; Theebaa Anasamy; Kuan Beng Ng; Suvitha Syam; Ismail Adam Arbab; Heshu Sulaiman Rahman; Hapipah Mohd Ali

    2013-01-01

    Zerumbone (ZER) isolated from Zingiber zerumbet was previously encapsulated with hydroxypropyl- β -cyclodextrin (HP β CD) to enhance ZER's solubility in water, thus making it highly tolerable in the human body. The anticancer effects of this new ZER-HP β CD inclusion complex via apoptosis cell death were assessed in this study for the first time in liver hepatocellular cells, HepG2. Apoptosis was ascertained by morphological study, nuclear stain, and sub-G1 cell population accumulation with G...

  4. Genetic Variation in BCL2 3′-UTR Was Associated with Lung Cancer Risk and Prognosis in Male Chinese Population

    OpenAIRE

    Xu, Ping; Liu, Li; Wang, Jianzhong; Zhang, Kai; Hong, Xiaohua; Deng, Qifei; Xiang, Jingjun; Zhang, Xiaomin; He, Meian; WU, TANGCHUN; Guo, Huan

    2013-01-01

    Objectives Bcl-2 is a critical apoptosis inhibitor with established carcinogenic potential, and can confer cancer cell resistance to therapeutic treatments by activating anti-apoptotic cellular defense. We hypothesized that genetic variants of BCL2 gene may be associated with lung cancer susceptibility and prognosis. Methods Three selected tagSNPs of BCL2 (rs2279115, rs1801018, and rs1564483) were genotyped in 1017 paired male Chinese lung cancer cases and controls by TaqMan assay. The associ...

  5. Increased expression of Bcl-2 during mucous cell metaplasia induced by endotoxin and ozone

    Energy Technology Data Exchange (ETDEWEB)

    Tesfaigzi, J.; Ray, L.M.; Hotchkiss, J.A. [Michigan State Univ., East Lansing, MI (United States)] [and others

    1995-12-01

    Apoptosis or programmed cell death is accompanied by characteristic morphological changes that distinguish apoptosis from other forms of cell death. These changes include DNA fragmentation, chromatin condensation, cell shrinkage, cell surface pseudopodia, and finally the cellular collapse into membrane-enclosed apoptotic bodies which are rapidly engulfed by macrophages or neighboring cells. Although the morphological features of apoptotic cells are well studied, the biochemical events that control apoptosis are not understood. Programmed cell death is triggered by a variety of pathways that are initiated by different stimuli including noxious agents, DNA damage, the activation of TNF receptors, or the withdrawl of growth factors. The central process of programmed cell death involves a cascade of biochemical events that begins with the initiation of a family of cysteine proteases, including the interleukin-1-{Beta}-converting enzyme, CPP-32, and Apopain. The ratio of Bax, a death-inducer gene, to Bcl-2, an apoptosis suppressor gene, determines whether or not the main apoptotic pathyway is blocked. Apoptosis is suppressed if the ratio of Bcl-2/Bax is > 1, and cells undergo apoptosis if the ratio is < 1. The overexpression of Bcl-2 has been shown to block the apoptotic program triggered by a variety of agents. Therefore, Bcl-2 must be involved in blocking the central pathway of the cell death program. In conclusion, this study showed that high levels of Bcl-2 were detected in some mucous cells at specific time points during mucous cell metaplasia, and this expression was reduced at later time points or was absent after remodeling of this epithelium.

  6. Differential anti-tumor activity of coriolus versicolor (Yunzhi) extract through p53- and/or Bcl-2-dependent apoptotic pathway in human breast cancer cells.

    Science.gov (United States)

    Ho, Cheong-Yip; Kim, Chi-Fai; Leung, Kwok-Nam; Fung, Kwok-Pui; Tse, Tak-Fu; Chan, Helen; Lau, Clara Bik-San

    2005-06-01

    Coriolus versicolor (CV), also called Yunzhi, has been demonstrated to exert anti-tumor effects on various types of cancer cells, but the underlying mechanism has not been fully elucidated. The present study aimed to evaluate the in vitro anti-tumor activity of a standardized aqueous ethanol extract prepared from CV on four breast cancer cell lines using MTT assay, and test whether the mechanism involves apoptosis induction and modulation of p53 and Bcl-2 protein expressions using cell death detection ELISA, p53 and Bcl-2 ELISAs respectively. Our results demonstrated that the CV extract dose-dependently suppressed the proliferation of three breast tumor cell lines, with ascending order of IC50 values: T-47D, MCF-7, MDA-MB-231, while BT-20 cells were not significantly affected. Tumoricidal activity of the CV extract was found to be comparable to a chemotherapeutic anti-cancer drug, mitomycin C. Nucleosome productions in apoptotic MDA-MB-231, MCF-7 and T-47D cells were significantly augmented in a time-dependent manner and paralleled the anti-proliferative activity of CV extract. Expression of p53 protein was significantly upregulated only in T-47D cells treated with the CV extract in a dose- and time-dependent fashion, but not in MCF-7 (except at 400 mug/ml after 16 h) and MDA-MB-231 cells. The CV extract significantly induced a dose-dependent downregulation of Bcl-2 protein expression in MCF-7 and T-47D cells, but not in MDA-MB-231 cells. These results suggested that apoptosis induction, differentially dependent of p53 and Bcl-2 expressions, might be the possible mechanism of CV extract-mediated cytotoxicity in human breast cancer cells in vitro. PMID:15908782

  7. Increased cytotoxicity of ionizing radiation in combination with membrane-targeted apoptosis modulators involves downregulation of protein kinase B/Akt-mediated survival-signaling

    International Nuclear Information System (INIS)

    Background and purpose: The membrane-targeted apoptosis modulators erucylphosphocholine (ErPC) and erucylphosphohomocholine (ErPC3) induce apoptosis in highly apoptosis resistant malignant glioma cell lines and enhance radiation-induced cell death and eradication of clonogenic tumor cells in vitro. Aim of the present study was to elucidate molecular mechanisms of combined action. Materials and methods: Induction of apoptosis was evaluated by determination of nuclear morphology (fluorescence microscopy), alteration of mitochondrial function and caspase-activation (flow cytometry, Western blot). Activity of protein kinase B (PKB/Akt) and key downstream effectors involved in apoptosis regulation was verified by Western blot analysis using activation-specific antibodies. Results: Increased cytotoxicity of the combination was linked to a more efficient activation of the intrinsic apoptosis pathway with increased damage of the mitochondria and caspase-activation. Moreover, activity of the survival kinase PKB/Akt was downregulated upon treatment with ErPC/ErPC3 alone or in combination with ionizing radiation. Inhibition of PKB/Akt was associated with decreased phosphorylation and thus activation of the pro-apoptotic Bcl-2 protein Bad as well as dephosphorylation of the transcription factor FOXO3A (FKHRL1) that may be responsible for the observed increased expression of the pro-apoptotic Bcl-2 protein Bim. Conclusions: Our data suggest a role for inhibition of PKB/Akt-mediated anti-apoptotic signaling in increased efficacy of the combination

  8. A Urinary Bcl-2 Surface Acoustic Wave Biosensor for Early Ovarian Cancer Detection

    Directory of Open Access Journals (Sweden)

    Nathan D. Gallant

    2012-05-01

    Full Text Available In this study, the design, fabrication, surface functionalization and experimental characterization of an ultrasonic MEMS biosensor for urinary anti-apoptotic protein B-cell lymphoma 2 (Bcl-2 detection with sub ng/mL sensitivity is presented. It was previously shown that urinary Bcl-2 levels are reliably elevated during early and late stages of ovarian cancer. Our biosensor uses shear horizontal (SH surface acoustic waves (SAWs on surface functionalized ST-cut Quartz to quantify the mass loading change by protein adhesion to the delay path. SH-SAWs were generated and received by a pair of micro-fabricated interdigital transducers (IDTs separated by a judiciously designed delay path. The delay path was surface-functionalized with monoclonal antibodies, ODMS, Protein A/G and Pluronic F127 for optimal Bcl-2 capture with minimal non-specific adsorption. Bcl-2 concentrations were quantified by the resulting resonance frequency shift detected by a custom designed resonator circuit. The target sensitivity for diagnosis and identifying the stage of ovarian cancer was successfully achieved with demonstrated Bcl-2 detection capability of 500 pg/mL. It was also shown that resonance frequency shift increases linearly with increasing Bcl-2 concentration.

  9. Increased lymphocyte apoptosis in mouse models of colitis upon ABT-737 treatment is dependent upon BIM expression

    OpenAIRE

    C. Lutz; M. Mozaffari; Tosevski, V; Caj, M; Cippà, P; McRae, B L; Graff, C L; Rogler, G; Fried, M; Hausmann, M

    2015-01-01

    Exaggerated activation of lymphocytes contributes to the pathogenesis of inflammatory bowel disease (IBD). Medical therapies are linked to the BCL-2 family-mediated apoptosis. Imbalance in BCL-2 family proteins may cause failure in therapeutic responses. We investigated the role of BCL-2 inhibitor ABT-737 for lymphocyte apoptosis in mice under inflammatory conditions. B.6129P2-interleukin (IL)-10(tm1Cgn) /J (IL-10(-/-) ) weighing 25-30 g with ongoing colitis were used. Fifty mg/kg/day ABT-737...

  10. Prognostic significance of bcl-2 and p53 expression in colorectal carcinoma

    Institute of Scientific and Technical Information of China (English)

    ZHAO Dan-ping; DING Xiao-wen; PENG Jia-ping; ZHENG Yi-xiong; ZHANG Su-zhan

    2005-01-01

    Objective: This study was designed to detect the expression ofbcl-2 and p53 proteins in colorectal carcinomas and to determine their association with the patient survival and stage of the diseases. Methods: Immunohistochemistry method was used to detect the expression ofbcl-2 and p53 proteins in 93 cases of colorectal carcinoma. The stain results were obtained by analyzing the clinic-pathological characteristics of patients. Results: Fifty-seven percent (53/93) of the colorectal carcinomas were bcl-2 protein positive. The positive rate of bcl-2 protein in lymph node involvement cases was lower (15/37) than the cases without node involvement (38/58, P<0.01). The positive rate of p53 protein was 43% (40/93) in colon-rectum carcinomas. No significant correlation was observed between p53 protein expression and clinic-pathological manifestations (P>0.05) but the survival was significantly worse (P=0.0001) in the p53 protein positive cases. Neither bcl-2 nor p53 alone was correlated with stage of the disease. When combined bcl-2/p53 status was analyzed, a group with bcl-2(+) and p53(-) had the best prognosis. This group was significantly associated with earlier Dukes' stages (P=0.1763). In multivariate Cox regression analysis, lymph node involvement and p53 protein expression were two independent factors correlated with survival time. Conclusion: The expression of bcl-2 and p53 represent biological characteristics of colorectal carcinomas. Assessment of both bcl-2 and p53 status may be valuable in predicting the prognosis of patients.

  11. Targeting anti-apoptotic Bcl-2 by AT-101 to increase radiation efficacy: data from in vitro and clinical pharmacokinetic studies in head and neck cancer

    International Nuclear Information System (INIS)

    Pro-survival Bcl-2 family members can promote cancer development and contribute to treatment resistance. Head and neck squamous cell carcinoma (HNSCC) is frequently characterized by overexpression of anti-apoptotic Bcl-2 family members. Increased levels of these anti-apoptotic proteins have been associated with radio- and chemoresistance and poor clinical outcome. Inhibition of anti-apoptotic Bcl-2 family members therefore represents an appealing strategy to overcome resistance to anti-cancer therapies. The aim of this study was to evaluate combined effects of radiation and the pan-Bcl-2 inhibitor AT-101 in HNSCC in vitro. In addition, we determined human plasma levels of AT-101 obtained from a phase I/II trial, and compared these with the effective in vitro concentrations to substantiate therapeutic opportunities. We examined the effect of AT-101, radiation and the combination on apoptosis induction and clonogenic survival in two HNSCC cell lines that express the target proteins. Apoptosis was assessed by bis-benzimide staining to detect morphological nuclear changes and/or by propidium iodide staining and flow-cytometry analysis to quantify sub-diploid apoptotic nuclei. The type of interaction between AT-101 and radiation was evaluated by calculating the Combination Index (CI) and by performing isobolographic analysis. For the pharmacokinetic analysis, plasma AT-101 levels were measured by HPLC in blood samples collected from patients enrolled in our clinical phase I/II study. These patients with locally advanced HNSCC were treated with standard cisplatin-based chemoradiotherapy and received dose-escalating oral AT-101 in a 2-weeks daily schedule every 3 weeks. In vitro results showed that AT-101 enhances radiation-induced apoptosis with CI’s below 1.0, indicating synergy. This effect was sequence-dependent. Clonogenic survival assays demonstrated a radiosensitizing effect with a DEF37 of 1.3 at sub-apoptotic concentrations of AT-101. Pharmacokinetic analysis

  12. Drosophila larvae lacking the bcl-2 gene, buffy, are sensitive to nutrient stress, maintain increased basal target of rapamycin (Tor signaling and exhibit characteristics of altered basal energy metabolism

    Directory of Open Access Journals (Sweden)

    Monserrate Jessica P

    2012-07-01

    Full Text Available Abstract Background B cell lymphoma 2 (Bcl-2 proteins are the central regulators of apoptosis. The two bcl-2 genes in Drosophila modulate the response to stress-induced cell death, but not developmental cell death. Because null mutants are viable, Drosophila provides an optimum model system to investigate alternate functions of Bcl-2 proteins. In this report, we explore the role of one bcl-2 gene in nutrient stress responses. Results We report that starvation of Drosophila larvae lacking the bcl-2 gene, buffy, decreases survival rate by more than twofold relative to wild-type larvae. The buffy null mutant reacted to starvation with the expected responses such as inhibition of target of rapamycin (Tor signaling, autophagy initiation and mobilization of stored lipids. However, the autophagic response to starvation initiated faster in larvae lacking buffy and was inhibited by ectopic buffy. We demonstrate that unusually high basal Tor signaling, indicated by more phosphorylated S6K, was detected in the buffy mutant and that removal of a genomic copy of S6K, but not inactivation of Tor by rapamycin, reverted the precocious autophagy phenotype. Instead, Tor inactivation also required loss of a positive nutrient signal to trigger autophagy and loss of both was sufficient to activate autophagy in the buffy mutant even in the presence of enforced phosphoinositide 3-kinase (PI3K signaling. Prior to starvation, the fed buffy mutant stored less lipid and glycogen, had high lactate levels and maintained a reduced pool of cellular ATP. These observations, together with the inability of buffy mutant larvae to adapt to nutrient restriction, indicate altered energy metabolism in the absence of buffy. Conclusions All animals in their natural habitats are faced with periods of reduced nutrient availability. This study demonstrates that buffy is required for adaptation to both starvation and nutrient restriction. Thus, Buffy is a Bcl-2 protein that plays an

  13. Effect of Exercise Training on Bcl-2 and Bax Gene Expression in the Rat Heart

    OpenAIRE

    Jafari; Pourrazi; Nikookheslat; Baradaran

    2015-01-01

    Background Apoptosis or programmed cell death plays an important role in the development of cardiovascular diseases, particularly heart failure. Current evidence suggests that exercise training may alter apoptosis-related signaling in sensitive somatic tissues such as the myocardium. Objectives The aim of this study was to assess the effect of exercise training on Bcl-2 and Bax genes expression as key molecules involved in intrins...

  14. Effect of amlodipine on apoptosis of human breast carcinoma MDA-MB-231 cells

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Objective: To elucidate the effects of amlodipine on the proliferation and apoptosis of human breast carcinoma MDA-MB-231 cells. Methods: Light microscopy was used to determine the effects of amiodipine on cell morphology; Flow cytometry was used to quantitate cells undergoing apoptosis; the expression of a cell cycle-related protein, proliferating cell nuclear antigen (PCNA) and an antiapoptosis protein, Bcl-2 were assessed by immunocytochemistry. Results: Amlodipine concentration of 8.25 Ixmol/L (1/2 of IC50) affected the morphology, decreased the expression of PCNA and Bcl-2 and induced apoptosis of human breast carcinoma MDA-MB-231 cells. Conclusion: The effect of amlodipine on the antiproliferation of human breast carcinoma MDA-MB-231 cells is related to inducement of apoptosis, and the decrease of the expression of Bcl-2 and PCNA may be the possible mechanism for proliferation inhibitory and inducement of apoptosis.

  15. High expression of BCL-2 predicts favorable outcome in non-small cell lung cancer patients with non squamous histology

    International Nuclear Information System (INIS)

    Bcl-2 promotes cell survival by inhibiting adapters needed for the activation and cleavage of caspases thus blocking the proteolytic cascade that ultimately dismantles the cell. Bcl-2 has been investigated as a prognostic factor in non small cell lung cancer (NSCLC) patients with conflicting results. Here, we quantitatively assessed Bcl-2 expression in two large and independent cohorts to investigate the impact of Bcl-2 on survival. AQUA®, a fluorescent-based method for analysis of in situ protein expression, was used to measure Bcl-2 protein levels and classify tumors by Bcl-2 expression in a cohort of 180 NSCLC patients. An independent cohort of 354 NSCLC patients was used to validate Bcl-2 classification and evaluate outcome. Fifty % and 52% of the cases were classified as high expressers in training and validation cohorts respectively. Squamous cell carcinomas were more likely to be high expressers compared to adenocarcinomas (63% vs. 45%, p = 0.002); Bcl-2 was not associated with other clinical or pathological characteristics. Survival analysis showed that patients with high BCL-2 expression had a longer median survival compared to low expressers (22 vs. 17.5 months, log rank p = 0.014) especially in the subset of non-squamous tumors (25 vs. 13.8 months, log rank p = 0.04). Multivariate analysis revealed an independent lower risk for all patients with Bcl-2 expressing tumors (HR = 0.53, 95% CI 0.37-0.75, p = 0.0003) and for patients with non-squamous tumors (HR = 0.5, 95% CI 0.31-0.81, p = 0.005). Bcl-2 expression defines a subgroup of patients with a favorable outcome and may be useful for prognostic stratification of NSCLC patients

  16. Study on apoptosis in HL-60 cells and its related gene regulation induced by enriched uranium

    International Nuclear Information System (INIS)

    Objective: To study characteristics of injury in apoptosis of HL-60 cells and its related genes bcl-2 and bax expression induced by enriched uranium 235U. Methods: DNA gel electrophoresis was used to show the apoptosis of HL-60 cells. Immunohistochemical technique was used to identity the expression of bcl-2 and bax proteins in HL-60 cells, meanwhile RNA dot blot hybridization was used to show the expression of bcl-2 mRNA in HL-60 cells. Results: HL-60 cells irradiated with 235U displayed characteristics of DNA ladder formation in apoptotic cells. While the expression of bcl-2 protein was as high as (88±7)% in unirradiated control cells, down-regulation [lowered to (61±5)%] of its expression was noted after exposure to 235U. The expression of bax protein was low in control cells ,and after irradiation it did not change obviously. A marked down-regulation of bcl-2 mRNA expression was found in irradiated HL-60 cells. Conclusion: Progression of apoptosis in HL-60 cells induced by 235U is dependent on the time elapse of 235U irradiation. The apoptotic action of 235U in HL-60 cells is associated with down-regulation of the apoptosis-related gene bcl-2

  17. Azorella compacta methanolic extract induces apoptosis via activation of mitogen-activated protein kinase.

    Science.gov (United States)

    Sung, Min Hee; Kwon, Ok-Kyoung; Oh, Sei-Ryang; Lee, Joongku; Park, Sang-Hong; Han, Sang Bae; Ahn, Kyung-Seop

    2015-11-01

    Azorella compacta Phil. (AC) is an alpine medicinal plant used traditionally for antibacterial treatment. Recent studies have revealed that this plant also has anti‑diabetic effects, but that it is toxic. The present study investigated the underlying mechanisms of action of AC extract against human leukemia HL60 cells. Apoptosis induction was measured by MTT assay, fluorescence microscopy, DNA fragmentation assay, flow cytometric analysis, reverse transcription quantitative polymerase chain reaction and western blot analyses. It was found that AC extract inhibited the growth of HL60 and other cancer cell lines in a dose‑dependent manner. The cytotoxic effects of AC extract on HL60 cells were associated with apoptosis characterized by DNA fragmentation and dose‑dependent increases in Annexin V‑positive cells, as determined by flow cytometric analysis. AC‑extract‑induced apoptosis was accompanied by activated/cleaved caspase‑3, caspase‑9 and poly(adenosine diphosphate‑ribose) polymerase (PARP). The increases in apoptosis were also associated with decreases of the apoptosis-inhibitor B-cell lymphoma 2 (Bcl‑2), upregulation of pro‑apoptotic Bcl-2-associated X (Bax) protein and downregulation of anti‑apoptotic Bcl extra large protein. Furthermore, western blot analysis of mitogen-activated protein kinase (MAPK)-associated proteins indicated that treatment with AC extract increased the levels of c-Jun N-terminal kinase, extracellular signal-regulated kinase and p38. In addition, the expression of Bax and cleaved PARP was blocked when AC treatment was performed in the presence of MAPK inhibitors. It was therefore concluded that AC induced apoptosis in human leukemia HL60 cells via an intrinsic pathway controlled through MAPK-associated signaling. PMID:26397193

  18. Enhanced sensitivity of BIU87 cells to cisplatin by bcl-2 antisense oligodeoxynucleotides%bcl-2反义寡核苷酸增强膀胱癌细胞株BIU87对顺铂的敏感性

    Institute of Scientific and Technical Information of China (English)

    王志华; 曾星; 胡志全; 叶章群; 王冀; 李有元; 刘双林; 鲁海洋; 邓康俐

    2011-01-01

    Objective To observe the influence of bcl-2 antisense oligodeoxynucleotides (ASON)on reversal of cisplatin resistance in BIU87 cell line of bladder carcinoma. Methods Cisplatin resistance bladder carcinoma cells served as models. The bcl-2 antisense oligodeoxynucleotides were transfected to the cells by lipofectamine and electroporation. The sense-and random-oligodeoxynucleotides were used as controls. The expression level of bcl-2 mRNA was detected by using semi-quantitative reverse transcription polymerase chain reaction ( RT-PCR) . The apoptosis of bladder cancer cell lines was examined by DNA ladder assay. The protein level and 50% inhibitory concentration (IC50) were measured by immunofluorescence technique and methyl thiazol tetrazolium (MTT) assay, respectively. Results Transfecting BIU87/DDP cells with antisense oligonucleotides statistically reduced IC50, values of BID/DDP cells from (66. 000 ±4. 637) to (20. 400 ±2. 590) mg/L. Twelve h after transfection by lipofectamine, 30% cells had apoptotic or necrotic changes under the inverted phase contrast microscopy, and DNA " Ladder" was observed with agrose gel electrophoresis in the antisense-transfected cells. Forty-eight h after transfection by electroporation followed by treatment of 10 mg/L cisplatin, RT-PCR showed the expression of bcl-2 mRNA in the transfected cells was significantly lower (0. 72 ± 0. 07 ) than before transfection ( 2. 94 ± 0. 09 ) , and that of bcl-2 protein was decreased, as well as the IC50. Conclusion bcl-2 antisense oligodeoxynucleotides can reverse the resistance to cisplatin in BIU87/DDP cells by inhibiting the expression of bcl-2 protein and increasing the apoptosis.%目的 观察bcl-2反义寡核苷酸对膀胱癌顺铂(DDP)耐药细胞耐药性的逆转并增强其敏感性的作用.方法 以膀胱癌顺铂耐药细胞株BIU87/DDP为模型,用脂质体转染和电转染的方法,将bcl-2反义寡核苷酸(bcl-2-AODN)转染BIU87/DDP细胞,同时以转染bcl-2

  19. Acetogenins from Annona muricata as potential inhibitors of antiapoptotic proteins: a molecular modeling study

    OpenAIRE

    Antony P; Vijayan R

    2016-01-01

    Priya Antony, Ranjit Vijayan Department of Biology, College of Science, United Arab Emirates University, Al Ain, Abu Dhabi, United Arab Emirates Abstract: Apoptosis is a highly regulated process crucial for maintaining cellular homeostasis and development. The B-cell lymphoma 2 (Bcl-2) family of proteins play a crucial role in regulating apoptosis. Overexpressed Bcl-2 proteins are associated with the development and progression of several human cancers. Annona muricata is a tropical pl...

  20. Increased expression of 78 kD glucose-regulated protein promotes cardiomyocyte apoptosis in a rat model of liver cirrhosis

    Science.gov (United States)

    Zhang, Lili; Zhang, Huiying; Lv, Minli; Jia, Jiantao; Fan, Yimin; Tian, Xiaoxia; Li, Xujiong; Li, Baohong; Ji, Jingquan; Wang, Limin; Zhao, Zhongfu; Han, Dewu; Ji, Cheng

    2015-01-01

    Aims: This study was to investigate the role and underlying mechanism of 78 kD glucose-regulated protein (GRP78) in cardiomyocyte apoptosis in a rat model of liver cirrhosis. Methods: A rat model of liver cirrhosis was established with multiple pathogenic factors. A total of 42 male SD rats were randomly divided into the liver cirrhosis group and control group. Cardiac structure analysis was performed to assess alterations in cardiac structure. Cardiomyocytes apoptosis was detected by TdT-mediated dUTP nick end labeling method. Expression of GRP78, CCAAT/enhancer-binding protein homologous protein (CHOP), caspase-12, nuclear factor kappa-light-chain-enhancer of activated B cells p65 subunit (NF-κB p65) and B cell lymphoma-2 (Bcl-2) was detected by immunohistochemical staining. Results: The ratios of left ventricular wall thickness to heart weight and heart weight to body weight were significantly increased with the progression of liver cirrhosis (P < 0.05). Apoptosis index of cardiomyocytes was significantly increased with the progression of liver cirrhosis (P < 0.05). The expression levels of GRP78, CHOP and caspase-12 were significantly increased in the progression of liver cirrhosis (P < 0.05). The expression levels of NF-κB p65 and Bcl-2 were highest in the 4-wk liver cirrhosis, and they were decreased in the 6-wk and 8-wk in the progression of liver cirrhosis. GRP78 expression levels were positively correlated with apoptosis index, CHOP and caspase-12 expression levels (P < 0.05). CHOP expression levels were negatively correlated with NF-κB p65 and Bcl-2 expression levels (P < 0.05). Conclusion: Increased expression of GRP78 promotes cardiomyocyte apoptosis in rats with cirrhotic cardiomyopathy. PMID:26464674

  1. Advanced oxidative protein products induced human keratinocyte apoptosis through the NOX-MAPK pathway.

    Science.gov (United States)

    Sun, Baihui; Ding, Ruoting; Yu, Wenlin; Wu, Yanhong; Wang, Bulin; Li, Qin

    2016-07-01

    Impaired wound healing is a major diabetes-related complication. Keratinocytes play an important role in wound healing. Multiple factors have been proposed that can induce dysfunction in keratinocytes. The focus of present research is at a more specific molecular level. We investigated the role of advanced oxidative protein products (AOPPs) in inducing human immortalized keratinocyte (HaCaT) cell apoptosis and the cellular mechanism underlying the proapoptotic effect of AOPPs. HaCaT cells were treated with increasing concentrations of AOPP-human serum albumin or for increasing time durations. The cell viability was measured using the thiazolyl blue tetrazolium bromide method, and flow cytometry was used to assess the rate of cell apoptosis. A loss of mitochondrial membrane potential (MMP) and an increase in intracellular reactive oxygen species (ROS) were observed through a confocal laser scanning microscope system, and the level of ROS generation was determined using a microplate reader. Nicotinamide adenine dinucleotide phosphate oxidase (NOX)4, extracellular signal-regulated kinase (ERK)1/2, p38 mitogen-activated protein kinase (MAPK), and apoptosis-related downstream protein interactions were investigated using the Western blot analysis. We found that AOPPs triggered HaCaT cell apoptosis and MMP loss. After AOPP treatment, intracellular ROS generation increased in a time- and dose-dependent manner. Proapoptotic proteins, such as Bax, caspase 9/caspase 3, and poly(ADP-ribose) polymerase (PARP)-1 were activated, whereas anti-apoptotic Bcl-2 protein was downregulated. AOPPs also increased NOX4, ERK1/2, and p38 MAPK expression. Taken together, these findings suggest that extracellular AOPP accumulation triggered NOX-dependent ROS production, which activated ERK1/2 and p38 MAPK, and induced HaCaT cell apoptosis by activating caspase 3 and PARP-1. PMID:27155970

  2. Epstein-Barr virus provides a new paradigm: a requirement for the immediate inhibition of apoptosis.

    Directory of Open Access Journals (Sweden)

    2005-12-01

    Full Text Available DNA viruses such as herpesviruses are known to encode homologs of cellular antiapoptotic viral Bcl-2 proteins (vBcl-2s, which protect the virus from apoptosis in its host cell during virus synthesis. Epstein-Barr virus (EBV, a human tumor virus and a prominent member of gamma-herpesviruses, infects primary resting B lymphocytes to establish a latent infection and yield proliferating, growth-transformed B cells in vitro. In these cells, 11 viral genes that contribute to cellular transformation are consistently expressed. EBV also encodes two vBcl-2 genes whose roles are unclear. Here we show that the genetic inactivation of both vBcl-2 genes disabled EBV's ability to transform primary resting B lymphocytes. Primary B cells infected with a vBcl-2-negative virus did not enter the cell cycle and died of immediate apoptosis. Apoptosis was abrogated in infected cells in which vBcl-2 genes were maximally expressed within the first 24 h postinfection. During latent infection, however, the expression of vBcl-2 genes became undetectable. Thus, both vBcl-2 homologs are essential for initial cellular transformation but become dispensable once a latent infection is established. Because long-lived, latently infected memory B cells and EBV-associated B-cell lymphomas are derived from EBV-infected proapoptotic germinal center B cells, we conclude that vBcl-2 genes are essential for the initial evasion of apoptosis in cells in vivo in which the virus establishes a latent infection or causes cellular transformation or both.

  3. Orphan Nuclear Receptor NR4A1 Binds a Novel Protein Interaction Site on Anti-apoptotic B Cell Lymphoma Gene 2 Family Proteins.

    Science.gov (United States)

    Godoi, Paulo H C; Wilkie-Grantham, Rachel P; Hishiki, Asami; Sano, Renata; Matsuzawa, Yasuko; Yanagi, Hiroko; Munte, Claudia E; Chen, Ya; Yao, Yong; Marassi, Francesca M; Kalbitzer, Hans R; Matsuzawa, Shu-Ichi; Reed, John C

    2016-07-01

    B cell lymphoma gene 2 (Bcl-2) family proteins are key regulators of programmed cell death and important targets for drug discovery. Pro-apoptotic and anti-apoptotic Bcl-2 family proteins reciprocally modulate their activities in large part through protein interactions involving a motif known as BH3 (Bcl-2 homology 3). Nur77 is an orphan member of the nuclear receptor family that lacks a BH3 domain but nevertheless binds certain anti-apoptotic Bcl-2 family proteins (Bcl-2, Bfl-1, and Bcl-B), modulating their effects on apoptosis and autophagy. We used a combination of NMR spectroscopy-based methods, mutagenesis, and functional studies to define the interaction site of a Nur77 peptide on anti-apoptotic Bcl-2 family proteins and reveal a novel interaction surface. Nur77 binds adjacent to the BH3 peptide-binding crevice, suggesting the possibility of cross-talk between these discrete binding sites. Mutagenesis of residues lining the identified interaction site on Bcl-B negated the interaction with Nur77 protein in cells and prevented Nur77-mediated modulation of apoptosis and autophagy. The findings establish a new protein interaction site with the potential to modulate the apoptosis and autophagy mechanisms governed by Bcl-2 family proteins. PMID:27129202

  4. hnRNP L binds to CA repeats in the 3'UTR of bcl-2 mRNA

    International Nuclear Information System (INIS)

    We previously reported that the CA-repeat sequence in the 3'-untranslated region (3'UTR) of bcl-2 mRNA is involved in the decay of bcl-2 mRNA. However, the trans-acting factor for the CA element in bcl-2 mRNA remains unidentified. The heterogeneous nuclear ribonucleoprotein L (hnRNP L), an intron splicing factor, has been reported to bind to CA repeats and CA clusters in the 3'UTR of several genes. We reported herein that the CA repeats of bcl-2 mRNA have the potential to form a distinct ribonuclear protein complex in cytoplasmic extracts of MCF-7 cells, as evidenced by RNA electrophoretic mobility shift assays (REMSA). A super-shift assay using the hnRNP L antibody completely shifted the complex. Immunoprecipitation with the hnRNP L antibody and MCF-7 cells followed by RT-PCR revealed that hnRNP L interacts with endogenous bcl-2 mRNA in vivo. Furthermore, the suppression of hnRNP L in MCF-7 cells by the transfection of siRNA for hnRNP L resulted in a delay in the degradation of RNA transcripts including CA repeats of bcl-2 mRNA in vitro, suggesting that the interaction between hnRNPL and CA repeats of bcl-2 mRNA participates in destabilizing bcl-2 mRNA.

  5. A multiple marker analysis of apoptosis-associated protein expression in non-small cell lung cancer in a Chinese population

    Directory of Open Access Journals (Sweden)

    En-Hua Wang

    2011-07-01

    Full Text Available A failure to undergo apoptosis is widely thought to be an important event in cancer formation and progression. Although there have been many studies in vitro that provide evidence for this suggestion, the roles of apoptosis-associated proteins in cancer tissues in vivo are not as yet fully understood. Moreover, multiple marker analyses of apoptosis-associated protein expression in non-small cell lung cancer (NSCLC tissues are scarce. In the present study, we investigate the expression of a group of apoptosis-associated proteins including bcl-2, caspase-3, fas, fas ligand (fasL and survivin, and its clinical significance in NSCLC tissues using immunohistochemistry (IHC. Bcl-2 staining in cancer tissue cells was found in cytoplasm and the positive rate was 38.2% (29/76. Caspase-3 staining was mainly seen in cytoplasm of cancer tissue cells (53.9% [41/76] with a few cases of nuclear staining (6.6% [5/76]. Fas staining was seen in cytomembrane (15.8% [12/76] and cytoplasm (42.1% [32/76] of cancer tissue cells. Likewise, fasL also showed staining in cytoplasm (55.3% [42/76] and cytomembrane (44.7% [34/76] of cancer tissue cells. Survivin staining was seen in cytoplasm but not nuclear of cancer tissue cells and the positive rate was 48.7% (37/76. Higher cytoplasm expression of bcl-2 was associated with large tumor size (≥ 3cm in NSCLC (p < 0.05. Decreased cytoplasm expression of fas was associated with poor grade in NSCLC (p < 0.05. A negative correlation was found between bcl-2 and cytoplasm caspase-3 expression in NSCLC (p < 0.001. No separate expression of the apoptosis-associated proteins in NSCLC was linked to overall survival of patients (p > 0.05. Multiple marker analyses revealed caspase-3+/cytomembrane fasL– to be linked to better survival of patients with NSCLC (p < 0.05. These results indicate that apoptosis- -associated proteins may impact a variety of clinicopathological features of NSCLC and may co-operatively influence

  6. Effect of fusion protein TAT and heme oxygenase-1 on liver sinusoidal endothelial cells apoptosis during preservation injury

    Institute of Scientific and Technical Information of China (English)

    YUE Li-hui; ZHAO Yan-li; CHEN Jing; LU Da-ru

    2010-01-01

    Background Proteins or peptides can be directly transferred into cells when covalently linked to protein transduction domains (PTDs). TAT is one of the most widely studied PTDs. The effect of fusion protein TAT and heme oxygenase-1 (HO-1) on liver sinusoidal endothelial cells (SECs) apoptosis during cold storage is unknown. The present study aimed to determine whether fusion protein TAT-HO-1 would transduce efficiently into liver during cold storage, and, if so, to determine whether TAT-HO-1 would attenuate SECs apoptosis during preservation injury in rat. Methods Livers of Sprague-Dawley rats were harvested and randomly assigned to group 1 (HTK solution) and group 2 (HTK solution containing TAT-HO-1 fusion protein) according to the type of the preservation solution. The transduction efficiency of TAT-HO-1 was examined and the impairment of SECs was assessed during the period of cold storage followed by 1 hour of reperfusion.Results TAT-HO-1 can transduce efficiently into liver during cold storage. A significantly lower apoptotic index of SECs was observed in group 2, at 6, 12 and 18 hours of cold storage after 1 hour reperfusion, when compared with group 1. TAT-HO-1 reduced HA and ET levels in liver at each time point. Both Bcl-2 and Bax protein were expressed in hepatocytes and SECs at the periphery of the sinusoidal space. Moreover, higher Bcl-2 expression and lower Bax expression were observed in group 2.Conclusions TAT-HO-1 can transduce efficiently into rat livers and shows a protective effect on SECs by attenuating apoptosis during cold ischemia/reperfusion injury. Protein transduction will be a novel therapeutic strategy to reduce the risk of preservation injury in liver transplantation.

  7. Clinical significance of P53 and Bcl-2 in acute myeloid leukemia patients of Eastern India

    Directory of Open Access Journals (Sweden)

    Geetaram Sahu

    2011-11-01

    Full Text Available The frequency of p53 and Bcl-2 protein expression in 100 newly diagnosed and 10 relapsed acute myeloid leukemia (AML patients was analyzed by immunocytochemistry (ICC. The Kaplan-Meier method was used for univariate and multivariate statistical analysis to assess the relationship between p53, Bcl-2 and clinico-hematologic feature with respect to overall survival (OS using SPSS statistical software. No statistical significance was found in univariate analysis (P=0.60. However, when the subgroups of patients (+1, +2, +3 and +4 were compared, expression of p53 and Bcl-2 protein (1-10%, 11- 30%, 31-50% and >50% was statistically significant (P<0.05. However, in multivariate analysis, p53, immunopositivity was independently associated with a shorter overall survival (OS (P=0.038 while Bcl-2 immunopositivity was associated with longer overall survival (OS (P=0.002. Our finding shows that p53 and Bcl-2 protein overexpression is a strong indicator of response to chemotherapy and overall survival. This study reports for the first time AML in patients from Eastern India.

  8. Activation of A2b adenosine receptor regulates ovarian cancer cell growth: involvement of Bax/Bcl-2 and caspase-3.

    Science.gov (United States)

    Hajiahmadi, Sima; Panjehpour, Mojtaba; Aghaei, Mahmoud; Shabani, Mahdi

    2015-08-01

    A2b adenosine receptor (A2bAR) acts as a potent regulator of cell growth in various cell lines. The present study was designed to understand the controlling mechanism of A2bAR agonist (NECA)-induced apoptosis in ovarian cancer cells. Real-time PCR and western blotting assays were used to evaluate the gene and protein expression profiles of A2bAR, respectively. MTT assay was used to study the cell proliferation effect of A2bAR agonist (NECA). Detection of apoptosis was conducted using annexin V-FITC/PI staining, caspase-3 activation assay, and the expression of Bax and Bcl-2 proteins analysis. The mitochondrial membrane potential (ΔΨM) was analyzed by employing JC-1 prob. The mRNA and protein expression levels of A2bAR in ovarian cancer cells were detected. NECA significantly reduced cell viability in a dose-dependent manner in OVCAR-3 and Caov-4 cell lines. The growth inhibition effect of NECA was related to the induction of cell apoptosis, which was manifested by annexin V-FITC staining, activation of caspase-3, and loss of mitochondrial membrane potentials (ΔΨm). In addition, downregulation of the regulatory protein Bcl-2 and upregulation of Bax protein by NECA were also observed. These findings demonstrated that NECA induces apoptosis via the mitochondrial signaling pathway. Thus, A2bAR agonists may be a potential agent for induction of apoptosis in ovarian cancer cells. PMID:25877700

  9. Memantine prevents cognitive impairment and reduces Bcl-2 and caspase 8 immunoreactivity in rats injected with amyloid β1-40.

    Science.gov (United States)

    Miguel-Hidalgo, José Javier; Paul, Ian A; Wanzo, Valerie; Banerjee, Pradeep K

    2012-10-01

    Amyloid-beta peptides (Aβ) can trigger apoptotic cascades in neurons. We found previously that memantine, an uncompetitive antagonist of N-methyl-D-aspartate (NMDA) receptors approved for the treatment of moderate to severe Alzheimer's disease, can prevent neurodegeneration induced by intracranial Aβ(1-40) injection. In this study, we tested the hypothesis that memantine prevents Aβ(1-40)-mediated cognitive impairment, neurodegeneration, and apoptosis of hippocampal neurons in rats. In addition, we hypothesized that Aβ(1-40) injection would induce changes in the levels of one or more apoptosis-related proteins, and that these changes would be attenuated by memantine treatment. Female Sprague-Dawley rats were administered memantine (continuous subcutaneous application, 9.6-14.4mg/kg/day; n=8) or vehicle (water; n=8) for 9 days. Two days after treatment initiation, the animals were bilaterally injected with Aβ(1-40) into the CA1/DG region of the hippocampus, subjected to active avoidance testing for 7 days, and sacrificed for immunohistochemical examination of four caspases (3, 6, 8, and 9) and three proteins of the Bcl-2 family (Bcl-2, Bax, and Bad). Injection of Aβ resulted in neurodegeneration, DNA fragmentation, increased Bcl-2 immunostaining, and significantly impaired performance in an active avoidance task, all which were significantly attenuated in rats treated with memantine. No differences in immunoreactivity of caspases 3, 6, 8, and 9 were discovered between groups after 7 days. Additional experiments demonstrated that an increase in caspase 8 immunostaining, observed 3 days after Aβ(1-40) injection, was significantly attenuated in memantine-treated rats. These data suggest that, in rats, memantine can prevent amyloid-triggered expression of apoptosis-related markers and concomitant cognitive deficits. PMID:22824463

  10. The effect of Ginkgo biloba extract treatment in the Bcl-2 expression by osteoblasts in the femoral trabecular bone of Wistar rats with glucocorticoid-induced osteoporosis

    Directory of Open Access Journals (Sweden)

    Leda M.F. Lucinda

    2014-06-01

    Full Text Available Evaluate the effect of the extract of Ginkgo biloba L., Ginkgoaceae (EGb in the Bcl-2 expression by osteoblasts in the femoral trabecular bone of Wistar rats with glucocorticoid-induced osteoporosis. Rats were divided into five groups: osteoporosis; EGb1 (28 mg/kg; EGb2 (56 mg/kg; alendronate (0.2 mg/animal and control. The treatments were conducted for 20 or 30 days. The Bcl-2 expression by osteoblasts cells was evaluated in the femoral trabecular bone. The control group was compared with the osteoporosis-induced group (Student's t-test. The other groups were analyzed by ANOVA test followed by Tukey's test (p < 0.05. The percentage of Bcl-2 expression was reduced, when the control group (17.95 ± 3.45 20 days; 21.11 ± 3.43 30 days was compared with the osteoporosis group (10.64 ± 3.30 20 days; 9.72 ± 2.84 30 days. Nevertheless, this percentage increased in the EGb2 group (18.58 ± 3.41 20 days; 16.51 ± 1.80 30 days when compared to the osteoporosis group. The EGb increased the expression of the anti-apoptotic protein, suggesting a decrease in osteoblast apoptosis.

  11. Neuroprotective effects of a chromatin modifier on ischemia/reperfusion neurons: implication of its regulation of BCL2 transactivation by ERα signaling.

    Science.gov (United States)

    Guo, Jun; Zhang, Tao; Yu, Jia; Li, Hong-Zeng; Zhao, Cong; Qiu, Jing; Zhao, Bo; Zhao, Jie; Li, Wei; Zhao, Tian-Zhi

    2016-06-01

    An understanding of the molecular mechanisms involved in the regulation of estrogen receptor alpha (ERα)-mediated neuroprotective effects is valuable for the development of therapeutic strategy against neuronal ischemic injury. Here, we report the upregulated expression of metastasis-associated protein 1 (MTA1), a master chromatin modifier and transcriptional regulator, in the murine middle cerebral artery occlusion (MCAO) model. Inhibition of MTA1 expression by in vivo short interfering RNA treatment potentiated neuronal apoptosis in a caspase-3-dependent manner and thereafter aggravated MCAO-induced neuronal damage. Mechanistically, the pro-survival effects of MTA1 required the participation of ERα signaling. We also provide in vitro evidence that MTA1 enhances the binding of ERα with the BCL2 promoter upon ischemic insults via recruitment of HDAC2 together with other unidentified coregulators, thus promoting the ERα-mediated transactivation of the BCL2 gene. Collectively, our results suggest that the augmentation of endogenous MTA1 expression during neuronal ischemic injury acts additionally to an endocrinous cascade orchestrating intimate interactions between ERα and BCL2 pathways and operates as an indispensable defensive mechanism in response to neuronal ischemia/reperfusion stress. Future studies in this field will shed light on the modulation of the complicated neuroprotective effects by estrogen signaling. PMID:26728277

  12. Temporal Alterations in Cellular Bax:Bcl-2 Ratio following Traumatic Brain Injury in the Rat

    OpenAIRE

    Raghupathi, Ramesh; Strauss, Kenneth I.; Zhang, Chen; Krajewski, Stanislaw; Reed, John C.; McIntosh, Tracy K.

    2003-01-01

    Cell death/survival following CNS injury may be a result of alterations in the intracellular ratio of death and survival factors. Using immunohistochemistry, Western analysis and in situ hybridization, the expression of the anti-cell death protein, Bcl-2, and the pro-cell death protein, Bax, was evaluated following lateral fluid-percussion (FP) brain injury of moderate severity (2.3–2.6 atm) in adult male Sprague-Dawley rats. By 2 h post-injury, a marked reduction of cellular Bcl-2-immunoreac...

  13. Expression of Bcl-2 and Bcl-xL in Cutaneous and Bone Marrow Lesions of Mastocytosis

    OpenAIRE

    Hartmann, Karin; Artuc, Metin; Baldus, Stephan E.; Zirbes, Thomas K.; Hermes, Barbara; Thiele, Juergen; Mekori, Yoseph A.; Henz, Beate M.

    2003-01-01

    Mastocytosis is a rare disease characterized by accumulation of mast cells in tissues. To investigate whether an altered regulation of mast cell apoptosis might be involved in the pathogenesis of mastocytosis, expression of the apoptosis-preventing molecules bcl-2 and bcl-xL was studied by immunohistochemistry in skin and bone marrow lesions of mastocytosis patients. In addition, reverse transcription-polymerase chain reaction was used to investigate levels of bcl-2 and bcl-xL mRNA in cutaneo...

  14. Garcinol potentiates TRAIL-induced apoptosis through modulation of death receptors and antiapoptotic proteins.

    Science.gov (United States)

    Prasad, Sahdeo; Ravindran, Jayaraj; Sung, Bokyung; Pandey, Manoj K; Aggarwal, Bharat B

    2010-04-01

    Whether garcinol, the active component of Garcinia indica, can modulate the sensitivity of cancer cells to TRAIL, a cytokine currently in phase II clinical trial, was investigated. We found that garcinol potentiated TRAIL-induced apoptosis of cancer cells as indicated by intracellular esterase activity, DNA strand breaks, accumulation of the membrane phospholipid phosphatidylserine, mitochondrial activity, and activation of caspase-8, -9, and -3. We found that garcinol, independent of the cell type, induced both of the TRAIL receptors, death receptor 4 (DR4) and DR5. Garcinol neither induced the receptors on normal cells nor sensitized them to TRAIL. Deletion of DR5 or DR4 by small interfering RNA significantly reduced the apoptosis induced by TRAIL and garcinol. In addition, garcinol downregulated various cell survival proteins including survivin, bcl-2, XIAP, and cFLIP, and induced bid cleavage, bax, and cytochrome c release. Induction of death receptors by garcinol was found to be independent of modulation of CCAAT/enhancer-binding protein-homologous protein, p53, bax, extracellular signal-regulated kinase, or c-Jun-NH(2)-kinase. The effect of garcinol was mediated through the generation of reactive oxygen species, in as much as induction of both death receptors, modulation of antiapoptotic and proapoptotic proteins, and potentiation of TRAIL-induced apoptosis were abolished by N-acetyl cysteine and glutathione. Interestingly, garcinol also converted TRAIL-resistant cells into TRAIL-sensitive cells. Overall, our results indicate that garcinol can potentiate TRAIL-induced apoptosis through upregulation of death receptors and downregulation of antiapoptotic proteins. Mol Cancer Ther; 9(4); 856-68. (c)2010 AACR. PMID:20371723

  15. Effects of acupoint versus non-acupoint electroacupuncture on cerebral cortical neuronal Bcl-2,Bax and caspase-3 expression in a rat model of focal cerebral ischemia

    Institute of Scientific and Technical Information of China (English)

    Jun Wang; Junming Fan; Yongshu Dong; Xia Huang; Hongxia Zhang

    2008-01-01

    BACKGROUND: Several studies have demonstrated that electroacupuncture by acupoint selection can inhibit cerebral cortical neuronal apoptosis following cerebral ischemia/reperfusion.OBJECTIVE: To validate the effects of electroacupuncture by acupoint selection on the expression level of cortical neuronal anti-apoptotic Bcl-2 protein and the apoptotic executive protein, caspase-3, in rat models of focal cerebral ischemia/reperfusion.DESIGN, TIME AND SETTING: This randomized grouping, neural cell and molecular biology animal experiment was performed at the Laboratory of Pharmacology of Traditional Chinese Medicine and the Laboratory Animal Center of Henan Institute of Traditional Chinese Medicine between November 2006 and May 2007.MATERIALS: Atotal of 40 healthy male adult Sprague-Dawley rats were randomly and evenly divided into four groups: sham-operated, model, electroacupuncture and non-acupoint control. G6895 electro-acupuncture instruments were purchased from Shanghai Huayi Instrument Factory, China. Caspase-3, Bcl-2 and Bax kits were provided by Wuhan Boster Bioengineering Co., Ltd., China.METHODS: Middle cerebral artery occlusion was induced in the model, electroacupuncture and non-acupoint groups. In the electroacupuncture group, the acupoints Jianyu (LI15), Waiguan (SJ5), Biguan (ST31), and Zusanli (ST36) were given electroacupuncture. In the non-acupoint control group, at each time point (immediately after ischemia and after reperfusion, or 2 hours after reperfusion), electroacupuncture was performed at the midpoints of Tianquan (PC2)-Quze (PC 3) line, Quze (PC 3)-Ximen (PC4) line, Zuwuli (LRlO)-Yinbao (LRg) line, and Xiguan (LR7)-Zhongdu (LR6) line. Electroacupuncture parameters were set with a continuous wave with a frequency of 10 Hz, wave width 0.6 ms, voltage 1.5-3.0 V, and a duration of 10 minutes. The sham-operated and model groups received only animal fixation without electroacupuncture procedure.MAIN OUTCOME MEASURES: Five rats were selected from

  16. The BH3 Only Protein Mimetic Obatoclax Sensitizes Cholangiocarcinoma Cells to Apo2L/TRAIL-Induced Apoptosis

    Science.gov (United States)

    Mott, Justin L.; Bronk, Steve F.; Mesa, Ruben A.; Kaufmann, Scott H.; Gores, Gregory J.

    2008-01-01

    Human cholangiocarcinomas evade apoptosis by overexpression of Mcl-1. The drug obatoclax (GX15–070) inhibits anti-apoptotic members of the Bcl-2 family including Mcl-1. Purpose To determine if obatoclax sensitizes human cholangiocarcinoma cells to apoptosis. Experimental Design The human cholangiocarcinoma cell lines, KMCH, KMBC, and TFK, were employed for these studies. Protein expression was assessed by immunoblot, and protein-protein interactions detected by co-precipitation of the polypeptide of interest with S-tagged Mcl-1. Activation of Bak and Bax was observed by immunocytochemistry with conformation specific antisera. Results Obatoclax induced minimal apoptosis alone; however, it increased apoptosis 3- to 13-fold in all three cancer cell lines when combined with Apo2L/TRAIL. Obatoclax did not alter cellular expression of Bid, Bim, Puma, Noxa, Bak, Bax, Mcl-1 or cFLIP. Mcl-1 binding to Bak was readily identified in untreated cells, and this association was disrupted by treating the cells with obatoclax. Additionally, Bim binding to Mcl-1 was markedly decreased by obatoclax treatment. We also identified alterations in Bak and Bax conformation following treatment with obatoclax plus Apo2L/TRAIL, but not with either Apo2L/TRAIL or obatoclax alone. Conclusions In conclusion, obatoclax releases Bak and Bim from Mcl-1 and sensitizes human cholangiocarcinoma cells to Apo2L/TRAIL-induced apoptosis. Obatoclax is a potentially promising adjunctive agent for the treatment of this cancer. PMID:18723481

  17. PUMA mediates ER stress-induced apoptosis in portal hypertensive gastropathy

    OpenAIRE

    Tan, S.; Wei, X; Song, M; Tao, J.; Yang, Y; Khatoon, S.; Liu, H.; J. Jiang; Wu, B

    2014-01-01

    Mucosal apoptosis has been demonstrated to be an essential pathological feature in portal hypertensive gastropathy (PHG). p53-upregulated modulator of apoptosis (PUMA) was identified as a BH3-only Bcl-2 fa